- Email: [email protected]
Mono-, Di-, and Oligosaccharides as Precursors for Polymer Synthesis
10.04 Mono-, Di-, and Oligosaccharides as Precursors for Polymer Synthesis J-P Pascault, Université de Lyon, INSA de Lyon, Lyon, France R Höfer, Editorial Ecosiris, Düsseldorf, Germany P Fuertes, Roquette Frères, Lestrem, France © 2012 Elsevier B.V. All rights reserved.
10.04.1 10.04.1.1 10.04.1.2 10.04.1.3 10.04.2 10.04.2.1 10.04.2.1.1 10.04.2.1.2 10.04.2.2 10.04.2.2.1 10.04.2.2.2 10.04.2.2.3 10.04.2.3 10.04.2.3.1 10.04.2.3.2 10.04.2.3.3 10.04.2.4 10.04.2.5 10.04.3 10.04.3.1 10.04.3.1.1 10.04.3.1.2 10.04.3.1.3 10.04.3.1.4 10.04.3.1.5 10.04.3.2 10.04.3.2.1 10.04.3.2.2 10.04.3.2.3 10.04.3.2.4 10.04.3.2.5 10.04.3.2.6 10.04.3.3 10.04.3.3.1 10.04.3.3.2 10.04.3.4 10.04.3.4.1 10.04.3.4.2 10.04.3.4.3 10.04.3.4.4 10.04.3.4.5 10.04.3.4.6 10.04.3.4.7 10.04.4 10.04.4.1 10.04.4.2 10.04.4.3 References
Introduction Biomass Building Blocks, Chemicals, and Potential Screening Aim of This Chapter Mono-, Di-, and Oligosaccharide-Based Platforms and Building Blocks Carbohydrate-Based C2 Polymer Building Blocks Ethanol production Bioethanol to ethylene and to other monomers Carbohydrate-Based C3 Polymer Building Blocks Lactic acid 1,3-Propanediol (1,3-PDO) 1,2-Propanediol (1,2-PDO) Carbohydrate-Based C4 Polymer Building Blocks Butanol and isobutanol Olefins The biosuccinic acid platform Carbohydrate-Based C5 Polymer Building Blocks Carbohydrate-Based C6 Polymer Building Blocks Carbohydrate-Based Polymers Polyolefins Polyethylene (PE) Polyvinyl chloride (PVC) Polypropylene (PP) C4-derived polymers Polyisoprene Thermoplastics Polyesters General considerations Polylactide acid and polyglycolic acid Aliphatic polyesters: poly(alkylene succinate)s Poly(hydroxyl alkanoates) Aromatic polyesters: poly(alkylene terephthalate)s Emerging polyesters Polyurethanes (PUs) and Polyureas General considerations Bio-based PUs Emerging Products Bio-based polyamides (PAs) Multisegmented block copolymers/TPEs (Meth)acrylic acid and (meth)acrylate families Polycarbonates Furan resins Unsaturated polyesters, UP thermosetting resins Thermosetting epoxy resins Conclusions Specificity of Bio-Based Polymers Commodity and Engineered Materials Future of Polymers from Renewable Resources
Polymer Science: A Comprehensive Reference, Volume 10
doi:10.1016/B978-0-444-53349-4.00254-5
60
60
61
61
62
62
62
63
64
64
64
65
65
65
66
66
67
68
70
70
70
70
71
71
71
71
71
72
73
73
74
74
74
74
75
75
75
75
75
76
77
77
78
78
78
79
79
79
59
60
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
chemistry, enzymatic conversion, and/or fermentation. These building blocks can be used directly or converted into monomers or precursors in order to prepare polymers through standard polymerization processes. 3. To produce bio-based polymers from microorganisms or genetically modified crops.
10.04.1 Introduction 10.04.1.1
Biomass
Biomass means all organic material of biogenic, nonfossil char acter and also comprises living and growing matter in nature and waste materials resulting from both living matter and organic matter that is already dead; the term includes terrestrial and marine plant materials, their residues and by-products, as well as animal and municipal wastes. Specifically, carbohy drates such as starch, cellulose, and hemicellulose are biomass that is produced by plants during the photosynthesis process using sunlight energy, water, and carbon dioxide. Starch is a main constituent of rice, corn, potato, pea, and so on, whereas wood is made up of cellulose (40–50%), hemi cellulose (20–30%), and lignin (15–25%). Carbohydrates are a rich source of C, H, and O elements, which are basic components of organic compounds. Figure 1 gives the formulae of carbohydrates that can be isolated from bio-based feedstocks and that can be used for the production of bio-based polymers. There are three principal routes to produce bio-based polymers:
The first pathway is outside the scope of this chapter, while the third one is currently relevant only for the production of poly(hydroxyl alkanoates) (PHAs) and xanthan, a microbial polysaccharide made by industrial biosynthesis starting from glucose (see Chapter 10.11). This chapter, therefore, focuses mainly on the second pathway that is gaining importance through the development of biorefineries. As an example, sucrose (also called saccharose, or more com monly sugar, Figure 1(b)) is a disaccharide produced at the industrial scale from sugar beet or sugarcane. It is the most widely available low-molar-mass carbohydrate, but until now, sucrose has been mainly used for nutrition purposes or for the fermenta tion industry (e.g., to produce citric acid, bioethanol, and lactic acid) and only to a smaller extent as chemical feedstock. Sucrose is sensitive to acids, and decreasing pH value enhances its hydro lysis into monosaccharides (a mixture of glucose and fructose). The conversion to monosaccharides could also be performed enzymatically. Hydrolysis of a polysaccharide to monosacchar ides is nearly neutral energetically (–20 kJ mol−1 for the hydrolysis of sucrose to glucose and fructose). For bio-based chemical production from biomass, the key reactions involved are not only hydrolysis but also dehydration,
1. To make use of natural polymers such as cellulose, starch, chitin, and lignin, which may be physically or chemically modified and used alone or in combination with other polymers. 2. To produce bio-based chemical intermediates from oligo-, di-, and monosaccharides (Figures 1(a)–1(d)) by means of (a)
OH O
O HO
OH
OH O
O
HO
OH
OH O
O OH
HO
OH O
O OH O
HO
n OH
(b) OH OH O
O
OH
HO HO
OH
(C1)
O
OH
OH
HO
H OH
OH
O
(C2)
O
HO
OH
OH OH
OH
OH (d2)
(d1) OH HO
H OH
O
O
OH
HO
OH OH
OH
Figure 1 Formulae of (a) polysaccharides, n > 10 composed of long chains of monosaccharide units bound together by glycosidic bonds; oligosac charides have the same formula but with n = 3–10; (b) a disaccharide: sucrose; (c1 and c2) monosaccharides; D-glucose, which can exist in both a straight chain (c1) and a ring form (c2); (d1 and d2) D-xylose, d1 is the acyclic form and d2 is one cyclic hemiacetal isomer.
61
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
Fumaric acid
O HO O O
O OH
HO O
OH
HO
OH
HO NH2 O
O OH
HO
Malic acid
3-Hydroxypropionic acid
Amination
OH
Aspartic acid
O
OH
O Succinic acid
Fermentation Fermentation Krebs pathway
NH2
O
OH
HO
Fermentation Glucose
O
OH
Aspartic acid
O O
OH Dehydration
O
HO
O
Fermentation
O
O
OH OH
Hydrogenation
OH OH O Gluconic acid
OH OH O
OH 3-Hydroxybutyrolactone
Oxidation
O
OH
HO
HO
OH
HO
Fermentation and oxidation
NH2 Glutamic acid
Levulinic acid
Oxidation
Itaconic acid
HO
O
Hydroxymethylfurfural
OH
OH
O
HO
OH
O O
O
Dehydration
Fermentation
HO
OH
OH OH OH
HO
OH OH
OH OH O
Sorbitol
Glucaric acid
Figure 2 Top value-added chemicals from glucose. According to Werpy, T.; Petersen, G., Eds. Top Value Added Chemicals from Biomass: Vol. 1— Results of Screening for Potential Candidate from Sugars and Synthesis Gas, US Department of Energy, Office of Scientific and Technical Information, National Renewable Energy Laboratory No.: DOE/GO-102004-1992. www.osti.gov/bridge, 2004.1b
isomerization, aldol condensation, reforming, hydrogenation, and oxidation. As shown as an example in Figure 2, it is possible to produce a wide variety of potential products from a given carbohydrate reactant like glucose. For example, sorbitol, alkyl glycoside, and gluconic acid have already been widely developed for industrial purposes. A similar diagram can be proposed for pentoses (Figure 3). Pentoses are among the major components of hemicelluloses. Various agricultural residues such as corn fiber, corn stover, wheat straw, rice straw, and sugarcane bagasse contain about 20–40% hemicellulose. The second most important abundant polysaccharide in nature!
10.04.1.2 Building Blocks, Chemicals, and Potential Screening In the decade 2000–10, groups of experts from different coun tries have given documented opinions on the use of microorganisms (bacteria and fungi) to improve manufacturing processes and make new products from renewable bio-based feedstocks.1a–h A team from Pacific Northwest National Laboratory and National Renewable Energy Laboratory1b pro posed in 2004 a list of 12 potential bio-based chemicals by examining the potential markets for the building blocks and their derivatives and the technical complexity of the synthesis pathways. The 12 sugar-based multiple functional molecules are listed in Figure 4: 1,4-diacids (succinic, fumaric, and malic
acids), 2,5-furan dicarboxylic acid (FDCA), 3-hydroxypropionic acid (HPA), aspartic acid, glucaric acid, glutamic acid, itaconic acid, levulinic acid, 3-hydroxybutyrolactone, glycerol, sorbitol, and xylitol/arabinitol.1b Another report released in 2007 proposed additional build ing blocks as viable candidates: gluconic acid, lactic acid, malonic acid, propionic acid, citric and aconitic triacids, xylo nic acid, acetoin, furfural, levuglucosan, lysine, serine, and threonine.1d But as the development of a bio-based industry requires the evaluation of a broad range of conversion technologies, includ ing enzymatic, catalytic, and thermochemical processes, these previous reports do not give a closed list. As an example, evaluation in 2009 of recent technology advances provides a revised list of bio-based product opportunities from carbohy drates slightly different and focusing on: ethanol, furans, glycerol and derivatives, biohydrocarbons such as isoprene, lactic, succinic, hydroxypropionic and levulinic acids, and also sorbitol and xylitol.2 If these lists are important for the establishment of new biorefineries integrating biofuels and chemical productions, they have to be considered just as dynamic guides.
10.04.1.3
Aim of This Chapter
The aim of this chapter is to describe how carbohydrates can be used as supply alternatives for C2, C3, C4, C5, C6 platform
62
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
Xylose O
OH OH
HO OH
Hydrogenation
OH
OH
OH
HO
OH H3C Propylene glycol
OH OH
Xylitol
Oxidation OH HO Ethylene glycol OH
OH
HO
OH O
OH
OH
O
HO
OH
Xylaric acid
Glycerol 1f
Figure 3 Xylitol as a platform chemical. Source: Michigan Biotechnology Institute.
chemicals and how biosourced polymers can be produced from such carbohydrate-based building blocks. The chapter will be divided into two parts. The first part describes the synthesis of main building blocks that are or will be used to prepare poly mers similar to the ones from petrochemical industry or novel polymers. The second part relates how polymers based on renewable resources are made, their properties, and applica tions; it contains several subparts dealing with different families of polymers and a last one focusing on novel polymers that have growth potential.
10.04.2 Mono-, Di-, and Oligosaccharide-Based Platforms and Building Blocks 10.04.2.1 10.04.2.1.1
Carbohydrate-Based C2 Polymer Building Blocks Ethanol production
Industrial ethanol fermentation is one of the best existing off sets to a petrochemical refinery producing transportation fuel and a chemical raw material in one. The manufacturing process for bioethanol has been industrial state of the art since the Brazilian Proálcool initiative3 of the 1970s and is mostly accomplished by anaerobic batch fermentation.4 A variety of sugar crops can be used for producing bioethanol, including sugarcane, sugar beet, and sweet sorghum, all of which contain a large proportion of sucrose. After conditioning, an aqueous raw sugar juice (sucrose syrup) is extracted. Using starch crops such as corn or wheat adds an additional step, the depolymer ization of amylose and amylopectin structures by enzymatic
liquefaction and saccharification to yield glucose syrup (Figure 5). To make lignocellulose an amenable raw material for bioethanol, it needs to undergo treatments that release its monomeric sugars, which then can be converted by fermentation. The two main steps are as follows: (1) a pretreatment (by physical or chemical procedures) that releases hexoses and pentoses from hemicellulose; and (2) an enzymatic treatment (or, alternatively, hydrolysis by chemical procedures) that gen erates glucose from cellulose. Unlike sugarcane processing, in which hexoses such as glucose and fructose are the only monomers released, lignocellulose substrates release both pentoses and hexoses. Pentoses, however, are not easily fermented by Saccharomyces cerevisiae, the preferred microorganism in crop-based glucose fermentation. Although two groups of microorganisms, that is, enteric bacteria and some yeasts, are able to ferment pentoses, efficient ‘white biotechnology’ processes for ethanol produc tion based on hemicelluloses and lignin in a so-called Lignocellulosic Feedstock (LCF) biorefinery are still a subject of intensive research and have not yet been established industrially.6 As alternatives to batch fermentation, continuous processes have been developed in order to reduce production costs and to improve process efficiency and ethanol yield.7 Although there are several routes for the manufacture of synthetic ethanol starting from fossil ethylene, such as the indirect catalytic hydration or the direct gas phase hydration,
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
63
(a) 1,4-Diacids HO
HO
O
O
HO
O
HO O
OH
O
Succinic acid
O
OH
Fumaric acid
OH
Malic acid
(b) 2,5-Furan dicarboxylic acid (FDCA) O
O
O
HO
OH
FDCA
(c) 3-Hydroxy propionic acid (3-HPA); glucaric acid; glutamic acid O
O HO
OH
OH
O
OH OH
HO
HO
OH NH2
OH OH O Glucaric acid
3-HPA
O
Glutamic acid
(d) Itaconic acid; levulinic acid; 3-hydroxybutyrolactone O
O
O OH
HO
O
HO
O
O
Itaconic acid
OH 3-Hydroxybutyrolactone
Levulinic acid
(e) Glycerol, sorbitol, and xylitol/arabinitol OH
OH HO
OH Glycerol
OH
OH OH
HO OH OH Sorbitol
OH
HO
OH OH Xylitol
Figure 4 Formulae of the 12 sugar-based multiple functional molecules: (a) 1,4-diacids; (b) FDCA; (c) 3-HPA, glucaric acid, glutamic acid, (d) itaconic acid, levulinic acid, 3-hydroxybutyrolactone; (e) glycerol, sorbitol, and xylitol/arabinitol.1b
on a global scale, synthetic feedstocks play a minor role for industrial ethanol production. At the end of the 1990s, only 7% of overall output accounted for synthetic feedstocks. Roughly 60% of world ethanol production has been from sugar crops, both cane and beet, with most of the remainder coming from grain, with maize playing a dominant role.8
10.04.2.1.2
Bioethanol to ethylene and to other monomers
The steam cracking process, which employs petroleum frac tions and natural gas liquids as feedstocks, is the dominant method for large-scale ethylene production worldwide. However, the improved economics of sucrose fermentation makes bioethanol a highly interesting alternative feedstock and puts the ‘bioethanol-to-ethylene’ (BETE) technology in the center of a biomass value chain covering fermentable
carbohydrate raw materials, polymerizable intermediates, and key polymer commodities. Fuel-grade ‘dry’ bioethanol is rather easily dehydrated to ethylene in an isothermal tubular reactor using aluminum oxide/magnesium oxide catalyst. The practical ethylene purity is approximately 94%. The presence of water in the ethanol feed is detrimental to the dehydration reaction. The mechanism for the ethanol dehydration assumes a simulta neous reaction: diethyl ether is considered an intermediate and not a by-product (Figure 6). Its formation is favored mainly between 150 and 300 °C, while ethylene formation is predominant between 320 and 450 °C.3,9 Alternatively, zeolite catalysts allow the production of prac tically pure ethylene from aqueous ethanol. This also means that ethylene can be produced directly from ethanol fermenta tion broth in a one-step process; for example, a superacidic
64
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
Starting material
Production of sugar containing substrate
Production of ethanol C6H12O6
Sugar-containing biomass
Washing, crushing
Extraction of sugar juice
Starch-containing biomass
Washing, crushing
Dry milling wet milling
2 C2H5OH + 2 CO2
Fermentation
Saccharification
Separation Yeast
Lignocellulosecontaining biomass
Pretreatment delignification
Acid/enzymatic hydrolysis
Saccharification
Distillation/ rectification Mash Dehydration
By-products
Bioethanol Figure 5 Production processes for bioethanol.5
2 CH3CH2OH
CH3CH2OCH2CH3 + H2O
H2C = CH2 + 2 H2O
Figure 6 Mechanism for the ethanol dehydration.
ZSM-5 zeolite can catalyze the dehydration reaction at tem peratures as low as 170 °C and under atmospheric pressure.10 Nonetheless, stability of the catalyst is not fully satisfactory and developing ZSM-5 zeolite and more particularly microscale and nanoscale HZSM-5 zeolite catalysts with high efficiency under lower reaction temperature to substitute alumina cat alyst is a field of active research. Besides pure or doped alumina and zeolites, many other catalysts have been studied for ethylene production via ethanol dehydration.11 The reac tors are usually tube-array, fixed-bed reactors with low ethylene yield, and relatively high reaction temperature (350–450 °C), while fluidized bed and microreactor technol ogies are under investigation.12 Technical concepts and designs for biorefineries taking advan tage of the benefits of a fully integrated chemical processing unit that would go from sugarcane to upstream ethylene derivatives such as vinyl chloride monomer (VCM), ethylene oxide (EO), and polyethylene (PE) have been developed by various engineer ing companies. With already established infrastructures, integrative plant concepts such as the ‘Biorefinery Leuna’ vision might be a promising and pragmatic approach.6c,13
10.04.2.2
Carbohydrate-Based C3 Polymer Building Blocks
C3 bio-based building blocks are mainly produced from gly cerol, which is produced in huge amounts as a by-product of splitting fats and oil (see Chapter 10.03). However, the produc tion of lactic acid and 1,3-propanediol (PDO) by fermentation is one of the best examples of successful industrial develop ment of carbohydrate-sourced, bio-based monomers for making new polymers.
10.04.2.2.1
Lactic acid
Two different types of lactic acid (CH3-CH(OH)-C(O)OH; also known as 2-hydroxypropionic acid or milk acid) can be pro duced by fermentation: both L(+)- and D(–)-lactic acid can be obtained by using an appropriate bacterial or fungal strain. Lactic acid bacteria are classified into homofermentative and heterofermentative. Homofermentative lactic acid bacteria pro duce virtually a pure lactic acid, whereas heterofermentative lactic acid bacteria produce other products such as ethanol, formate, or acetic acid along with lactic acid. The main homofermentative lactic acid bacteria used for the production of lactic acid from different carbon sources are Lactococcus lactis, Lactobacillus delbrueckii, Lactobacillus helveticus, and Lactobacillus casei. Amylolytic bacteria such as Lactobacillus amylovorus can convert liquefied starch to lactic acid with a high productivity.14 The current strains for industrial production of L(+)-lactic acid allow very good yield and productivity to be achieved: product concentration in industrial fermentations goes up to 180 g l−1 with lactic acid yield of 90% of fermentable sugars and a production rate of 5 g l−1 h−1. A wide variety of carbohydrate sources such as molasses, corn syrup, whey, glucose, and sucrose can be used for lactic acid production. Thermophilic homofermentative lactobacteria have been widely used for lactic acid production but require a careful pH control between 5.5 and 6.5 using neutralizing agent during the fermentation. Consequently, the recovery of lactic acid usually generates a large amount of by-products such as calcium sulfate. In order to get rid of this main issue, commercial lactic acid fermentation has now been developed, which is carried out under acidic conditions.15
10.04.2.2.2
1,3-Propanediol (1,3-PDO)
1,3-PDO can be produced by fermentation from glycerol, with different strains such as Klebsiella pneumoniae, Clostridium butyr icum, Clostridium pasteurianum, and Citrobacter freundii.
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
Drawbacks of industrial fermentation using these strains are strong inhibition of 1,3-PDO production and by-products dur ing fermentation. There are no naturally occurring microorganisms known to produce 1,3-PDO from glucose. DuPont in collaboration with Genencor and Tate & Lyle has developed a recombinant pro duction organism as well as a fermentation process to produce 1,3-PDO from glucose.16 The strain is based on an Escherichia coli K12 substantially engineered in order to obtain outstanding performances compared to glycerol fermentation. However, the increasing availability of glycerol due to increas ing biodiesel production and subsequently falling prices of this raw material could make glycerol fermentations more attractive. Recently, a recombinant C. butyricum producing 1,3-PDO with low amount of butyrate, butanol, acetone, and lactate has been patented by Metabolic Explorer.17 In addition, the downstream process has also been optimized in order to produce a purified grade of 1,3-PDO.18a 1.3-PDO can be formulated into a variety of polymers, inter alia polyesters, polytrimethylene terephthalate (PTT), composites, adhesives and coatings.18b,c
10.04.2.2.3
1,2-Propanediol (1,2-PDO)
1,2-PDO or propylene glycol (PG), a C3 dialcohol, is a widely used chemical. It is currently produced by chemical means using a propylene oxide hydration process. It is a component of not only unsaturated polyester (UP) resins or polyur ethanes (PUs) but also coolants, antifreeze, and deicing fluids for aircraft and has been increasingly used as a replace ment for ethylene glycol, which is recognized as being more toxic. Alternatively, bio-based PG can be produced by thermoche mical conversion of glycerol or purified alditols such as sorbitol. The thermochemical routes consist of a hydrogenolysis reaction in which the starting compound is catalytically converted, under heating and reducing conditions, into a mixture of glycols. Depending on the catalyst used for the hydrogenolysis, high selectivities to 1,2- or 1,3-PDO can be obtained.19 Global Biochem is currently producing industrial quantities of 1,2-PDO from sorbitol. A fermentation process for
65
producing 1,2-PDO from sucrose using a metabolically engi neered E. coli strain has also been reported.20
10.04.2.3 10.04.2.3.1
Carbohydrate-Based C4 Polymer Building Blocks Butanol and isobutanol
Actually, C4 building blocks of industrial relevance, more par ticularly butadiene, butene, butane, butanol, and maleic anhydride, rely on fossil raw materials produced in the steam cracker as a by-product in the cracking of naphtha (light gaso line) to ethene and propene. Hydroformylation of propene yields n- and isobutanol (2-methyl-1-propanol) depending on reaction conditions. Butanol/diesel and butanol/gasoline blends can be used in unmodified or slightly modified engines as transportation fuel.4 Butanol does not absorb moisture from air. Its energy content of 29.2 MJ l−1 is higher than ethanol (19.6 MJ l−1) and compares well with gasoline (32 MJ l−1). The potential use as a biofuel has created considerable interest in biobutanol as com pared to fossil fuel and bioethanol, and this is even more so as biobutanol would also be an important building block for C4-derived polymers (Figure 7). Furthermore, the manufactur ing of n-butanol by fermentation was the industry standard until the 1950s. Starting from corn production is actually prac ticed again by Cathay Industrial Biotech in Shandong /China. Alternatively, Cobalt Technologies in a strategic alliance with Rhodia (a member of the Solvay group) is exploring sugar cane bagasse as a feedstock on site in Brazil.22 The acetone–butanol or acetone–butanol–ethanol (ABE) fermentation using the Weizman organism Clostridium acetobutylicum or Clostridium beijerinckii under anaerobic conditions produces the three sol vents in a ratio of ABE = 3:6:1.23 More recently, microbial fermentation technologies, which genetically alter E. coli to generate several higher chain alcohols from glucose, including 1-butanol, 2-methyl-1-butanol, and more particularly isobutanol, have been developed. The tech nologies metabolically engineer E. coli’s amino acid biosynthetic pathway to divert its 2-keto acid intermediates to aldehydes by 2-keto acid decarboxylases (KDCs) and then to (b) Glucose Transhydrogenase
(a)
2 NADH
Gasoline replacement
Biocatalyst Enzymes nutrients
Fuels
Liquids Chemicals
Solids Fermentation
Jet fuel replacement
2CO2
Acetolactate KARI
Distillation Milling
2 Pyruvate ALS
Diesel replacement
2 NADPH
NADPH
2,3-Dihydroxvy-isovalerate DHAD α-Keto-isovalerate
Plastics Biomass
Drying
Feed
products
KIVD
H2O
Isobutyraldehyde
Fibers
NADPH
ADH Isobutanol
Figure 7 (a) The biobutanol value chain (with the kind permission of Lanxess). (b) Metabolic pathway for the conversion of glucose to isobutanol.21
66
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
alcohols by alcohol dehydrogenases (ADHs).21,24 Alternatively, an isobutanol production platform based on the amino acid-producing Corynebacterium glutamicum showed an increased tolerance to isobutanol relative to E. coli.25
10.04.2.3.2
Olefins
In an acid-catalyzed elimination reaction involving the loss of H2O (dehydration), isobutanol can be converted into a mix ture of C4 olefins (1-butene, cis-2-butene, trans-2-butene, and isobutene),26 which then convert into a mixture of unreacted isobutene and 1,3-butadiene in a catalytic dehydrogenation reaction at elevated temperature and low pressure well known from petrochemical process technologies.24,27 Lanxess and Gevo have developed a process for the produc tion of isobutene from isobutanol derived from grain crops, sugarcane, as well as cellulose. Meanwhile, Global Bioenergies has engineered an initial series of bacterial strains that can produce isobutene by transforming glucose in vivo.28
10.04.2.3.3
The biosuccinic acid platform
• Maleic anhydride has traditionally been manufactured by the oxidation of benzene but is now predominantly produced by using n-butane as a feedstock (Figure 8):27b Maleic acid is manufactured by hydrolysis of maleic anhydride. There are, however, few applications for maleic acid, the major industrial use being the isomerization into fumaric acid.29 Fumaric acid occurs naturally in many plants and is named after Fumaria officinalis, a climbing annual plant, from which it was first isolated. Currently, industrial synthesis of fumaric acid is mostly based on catalytic isomer ization of maleic acid in aqueous solutions. However, it could also be produced from glucose by fungal fermentation by Rhizopus oryzae.30 Fumaric acid is an industrial bulk che mical with an annual consumption of nearly 130 000 mto in 2006. Fumaric acid is used as acidulant in the food and beverage industries; to react with rosin from crude tall oil (CTO) distillation for the manufacture of fortified rosin paper sizes; and in place of maleic anhydride in alkyd and UP resins. Malic acid (hydroxybutanedioic acid, HOOCCH (OH)CH2COOH) is produced by the hydration of either fumaric or maleic acid. It is also a natural acid found in green apples and other unripe fruits. It is a crystalline solid that is used as an acidulant as well as a flavoring agent in the processing of beverages, confections, food, and personal care products. • In contrast to the BETE value chain, carbohydrate-based C4 building blocks do not only substitute crude oil-derived crack C4 intermediates but also complement the platform
O
2 CH3CH2CH2CH3 + 7 O2
2
O + 8 H2O
O Figure 8 Synthesis of maleic anhydride from n-butane.
and provide new opportunities for C4-based polymers. This is in particular the case for succinic acid (butanedioic acid) that has been produced for the use as a natural antibiotic and general curative since it was derived by dry distillation from amber (which gave the name amber acid still used in the German language: Bernsteinsäure) for the first time (Gregorius Agricola, 1546). Although the bulk of the actual industrial production of succinic acid is made by hydroge nation of maleic anhydride and subsequent hydration, ‘white biotechnology’ is gaining considerable interest as an environmentally sound alternative. Succinic acid is a component of the Krebs cycle (also called tricarboxylic acid (TCA) cycle and citric acid cycle), the process by which aerobic organisms convert carbohydrates, fats, and proteins into carbon dioxide and water to generate a form of usable energy they need to grow and divide. This meta bolic process and thus the biosynthesis of succinic acid occurs in most plants, animals, fungi, and many bacteria. Furthermore, fermentation of glucose to yield succinic acid has distinct advantages. While during bioethanol produc tion, for example, 2 mol of inert waste CO2 per mole of glucose are formed, biosuccinic acid production is a CO2-fixing operation:31 Bioethanol fermentation : C6 H12 O6 → 2C2 H5 OH þ 2CO2 Biosuccinic acid fermentation : C6 H12 O6 þ 2CO2 → 2C4 H6 O4 Inter alia, Lee and coworkers32 have studied Actinobacillus succinogenes, Mannheimia succiniciproducens, and Anaerobiospirillum succiniciproducens isolated from bovine rumen as natural succinic acid overproducers for bacterial fermentation of glucose. More recently, Song and Lee,33a Bechthold et al.,33b and Cukalovic and Stevens33c have put together the many different microorganisms that have been screened and studied for biotechnological succinic acid pro duction. Stability of the microorganisms, handling, and the downstream purification, that is, the separation of by-products such as acetic acid, formic acid, lactic acid, and pyruvic acid, are still a major issue for industrial production. On the other hand, it has long been known that E. coli fermentation produces a mixture of formic, lactic, and succi nic acids – however, at low yield and with succinic acid as a minor component only.34 Indeed, the biochemical pathway of succinic acid production in E. coli proceeds in several conversion steps from pyruvic acid to oxaloacetic acid, which is then converted to malic acid, fumaric acid, and succinic acid. Bioengineering research at Argonne National Lab. and others using robust E. coli mutants succeeded in improving the yield of succinic acid as the final product.35 They could also show that this pathway allows for a con trolled synthesis of the intermediate malic and fumaric acids. If fumaric acid is the product of choice, the gene that codes for the enzyme responsible for the conversion of fumaric acid to succinic acid is deleted and the resulting organism will amass fumaric acid instead of succinic acid. If malic acid is the desired product, the gene that codes for the enzyme
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
responsible for the conversion of malic to fumaric acid is deleted to make a malic acid-producing organism. Production methods for fumaric acid including production by different fermentation processes have recently been reviewed by Roa Engel et al.36 • ‘White biotechnology’ for the industrial synthesis of succinic acid was first practiced in Pomacle/F by BioAmber, a joint venture of Agro-Industrie Recherche (ARD) and DNP Green Technology. The same year, 2010 Reverdia (DSM/Roquette), Mitsubishi/PTT, BASF/Purac, and Myriant/Uhde developed industrial-scale biosuccinic acid operations. Raw material for biosuccinic acid synthesis would be any sugar-containing feedstock including glucose syrup from hydrolyzed starch, grain sorghum, corn steep liquor from wet milling, lactose from whey, and lignocellulosic hydrolysate produced by acid or enzyme hydrolysis. As already mentioned, the separation of pure succinic acid from the fermentation broth is another critical issue. Several methods have been developed, such as acidulation, solvent extraction and crystallization, electrodialysis, preci pitation as Ca2+ or Mg2+ salt,37 the use of tri-n-octylamine as a reactive phase transfer extractant,38 or reactive distillation with ethanol.39 The latter method would allow the direct production of diethyl succinate as intermediate for further conversion, for example, by transesterification. The develop ment of metabolically engineered yeast strains enables the fermentation to be run at low pH and consequently avoids the production of large amounts of salt during the down stream process.40 Hydrogenation of succinic acid or its dialkyl esters leads to 1,4-butanediol (BDO)41 – as an alternative to other man ufacturing processes such as the Reppe process starting from
67
acetylene, Mitsubishi’s butadiene–acetic acid process, Kuraray’s propylene oxide/allyl alcohol technology, or Toyo Soda’s dichlorobutene process.27b The acid-catalyzed dehy dration of 1,4-BDO yields tetrahydrofuran (THF) (Figure 9). • 1,4-Diaminobutane is manufactured by adding hydrocya nic acid to acrylonitrile in the presence of an alkaline catalyst such as triethylamine and then hydrogenating the succinic dinitrile intermediate.42 Therefore, the direct bio synthesis that can be achieved using a microorganism with increased ornithine decarboxylase (ODC) activity and N-acetylglutamate formation activity is a highly attractive alternative.43 Preferably, the ODC-encoding gene is inter alia originating from E. coli.
10.04.2.4
Carbohydrate-Based C5 Polymer Building Blocks
Carbohydrate-based C5 platform chemicals are formed by depolymerization of hemicelluloses or by C1 abstraction from C6 carbohydrates such as the synthesis of levulinic acid from hydroxymethylfurfural (HMF). ‘Levulinic acid’ (4-oxo pentanoic acid) is an interesting intermediate for the synthesis of low-molar-mass chemicals. The oxidation of levu linic acid offers an alternative route for the synthesis of succinic acid.44 It is also well known that during glucose fermentation to produce wine, beer, or schnapps, small amounts of fusel alcohols (also called fusel oil), more particularly 1-propanol, 2-propanol, various isomers of butanol, and amyl alcohol, are formed as by-products. The same applies for the production of biobutanol and the genes involved in the production of inter mediates that are converted into fusel alcohol components are known. Controlled overexpression of these genes can be tuned to produce specifically amyl alcohol isomers such as 3-methyl 1-butanol (isopentyl alcohol and isobutyl carbinol) or OH
HO
1,4-Butanediol OH HO HO
O
Esterification
O MeOOC
COOMe
OH OH
Tetrahydrofuran
Fermentation
HOOC
O
-Butyrolactone
Hydrogenation COOH
O
Dehydration
Succinic acid HOOC
COOH
O
Fumaric acid
O Dehydrogenation cyclization
O
COOH COOH
Maleic acid
Figure 9 Succinic acid as a platform chemical. Adapted from Bozell, J. J.; Petersen, G. R. Green Chem. 2010, 12, 539.2 Reproduced by permission of The Royal Society of Chemistry.
68
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
2-methyl-1-butanol.21,45 Similar to the synthesis of butene and butadiene by dehydration of butanol, the dehydration of pen tanols such as 3-methyl-1-butanol or 2-methyl-1-butanol yields multiple C5 olefin isomers. Dehydrogenation of these pentene mixtures followed by appropriate separation technol ogies produces pure ‘isoprene’.21,44 Depolymerization of hemicelluloses (pentosans) by acid-catalyzed hydrolysis yields pentoses, principally xylose, which is then dehydrated to ‘furfural’. Pentosans are present in sugarcane bagasse, corncobs, cottonseed, and rice hulls, that is, in biomass waste of vegetable oil or sucrose production. Alternatively, chemical or enzymatic hydrolysis of wood would convert cellulose to glucose (e.g., for bioethanol or bio succinic acid production) and hemicelluloses to pentoses, which are then converted to furfural. Furfural as a C5 platform inter mediate is hydrogenated in the presence of a Cu2Cr2O5 catalyst yielding ‘furfuryl alcohol’, the starting monomer for furan resins (Figure 10). Decarbonylation of furfural yields furan which can be converted by catalytic hydrogenation into tetrahydrofuran (THF). However, this route is not widely practiced. The thermo/chemical or enzymatic hydrolysis of hemicellu loses from wheat straw or bran yielding a pentose syrup that can be converted into alkyl polypentosides (APPs) is a
promising route to new fully renewable surfactants as alterna tives to alkyl polyglucosides (APGs).46 On an industrial scale, APPs are manufactured in analogy to one of the two methods conventionally used for preparing APGs. The first method con sists of reacting the pentose syrup and the fatty alcohol directly in the presence of an acid catalyst in order to obtain the poly pentosides (Figure 11). The second method consists of carrying out glycosidation, in a first step, with a short-chain C1–C5 alcohol and, in a second step, making a transglycosidation, which consists of displacing the short-chain alcohol with a C12–18 fatty alcohol.48
10.04.2.5
Carbohydrate-Based C6 Polymer Building Blocks
• The six-carbon monosaccharide glucose is quasiomnipresent in nature. Glucose is one of the main products of photosynthesis and starts cellular respiration. Glucose serves as an energy carrier (blood glucose) and as a molecular component in energy storage or structural polysaccharides (e.g., starch or cellulose). Lactose, the predominant sugar in milk, is a glucose–galactose disaccharide; sucrose (also called
H2 –H2O; R = H
H2, –CO
CHO
O Furfural
Furfuryl alcohol CH2OH
O
THF O
R
O
O OH
HO HO
COOH + HCOOH Levulinic acid
OH
–H2O R = CH2OH [O]
HO O
CHO
HMF –H2O
OHC [O]
HO
OH
V, Co catalysts –H2O
HOOC
O
OH Fructose
O
COOH
FDCA 2
Figure 10 Synthesis and transformation of furans. Reproduced by permission of The Royal Society of Chemistry.
O HO
ROH, H+ OH
H
O O
O DP
H2O Figure 11 Synthesis of APP.47 Reproduced by permission of Elsevier.
CHO
Diformylfuran
OH
HO
O
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
saccharose) is a disaccharide of anomerically linked D-glucose and D-fructose. • As a C6 polymer building block, glucose is a particularly flexible feedstock that can be valorized by (1) degradation of the C6 framework yielding C2 (e.g., bioethanol), C3 (e.g., glycerol and 3-HPA), C4 (e.g., butanol, succinic, fuma ric, malic, and aspartic acids) or C5 (e.g., amyl alcohol and glutamic acid) platform chemicals, (2) derivatization by maintaining the C6 framework, and (3) conversion into >C6 organic compounds, leading to a wide variety of pro mising organic building blocks or intermediates.49–51 The β-D-fructofuranosyl α-D-glucopyranoside structure of sucrose is maintained in sucrose or sugar esters. Sucrose esters are nonionic, surface-active materials with very mild dermatological properties. They are manufactured by transesterification of sucrose with fatty acid methyl esters (FAME) in a polar solvent or an emulsion process or in a melt process where sucrose and FAME react without any solvent under heterogeneous alkaline catalysis (K2CO3). Selectivity is diffi cult to achieve and typically a mixture of mono-, di-, tri-, tetra-, and pentaesters are formed.49,52 However, selective formation of sugar monoesters can be achieved by enzyma tically catalyzed transesterification.53 Similarly, vinyl esters (VEs) and sugars can react in suitable organic and microaqu eous media under enzymatic catalysis yielding glycomonomers such as 6-O-vinyladipoyl-D-glucose (Figure 12). Such vinyl sugar esters can be polymerized by a radical polymerization reaction yielding glycopolymers, a class of
H2C
biodegradable polymers that contain carbohydrate moieties as pendant or terminal groups.54 • Glucose can be readily hydrogenated in a batch or continuous-slurry process yielding ‘sorbitol’. The catalysts are generally various types of supported nickel or Raney nickel. However, large-scale production of sorbitol uses corn starch (glucose syrup) as raw material. Besides the use as a feedstock in vitamin C synthesis and as humectants in foods, cosmetics, and medicinal products, sorbitol and other sugar alcohols such as mannitol and xylitol may be employed as building blocks for polymer synthesis. Dehydration of sorbitol in the presence of an acid catalyst forms ‘1,4-sorbitan’ which can react with fatty acids yielding sorbitan fatty acid esters.32 Sorbitan fatty acid esters (Span) and their polyglycol ethers (Tween or polysorbate) are oleo philic W/O and hydrophilic O/W emulsifiers, respectively. Indeed, Span and Tween have been kind of archetypes for the hydrophile–lipophile balance (HLB) concept developed by Griffin as a means to formulate stable aqueous emulsions of cosmetic or industrial oils.52,55 The double dehydration of sorbitol yields isosorbide (1,4:3,6-dianhydro-D-glucitol), while the triple dehydration of glucose and other hexoses generates 5-(hydroxymethyl) furfural (HMF), which can be oxidized to 2,5-furandicar boxylic acid (FDCA), any of which is an example for high-potential, C6-derived building blocks for the synthesis of new biopolymers (Figure 10).56 Potential chemicals that may be derived from FDCA are diols such as 2,5-dihydroxymethyl furan or 2,5-dihydroxymethyl
O O O O
CH2
Divinyl adipate HO
O
H2C O
OH
OH OH D-Glucose
O
O O
O
OH Protease from Bacillus subitillis, DMF/water(95/5) 50 °C, 5 days, 150 rpm
69
OH OH 6-O-Vinyladipoyl D-Glucose
OH OH
K2S2O8/H2O2, 60 °C, 24 h
H2 C
H C n O
O O
O
O OH
OH
OH Poly(6-O-Vinyladipoyl D-Glucose) Figure 12 Chemoenzymatic synthesis outline to produce the poly(6-O-vinyladipoyl-D-glucose).54c
OH
70
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
Hexoses O
HO
O
O O Furans O
H
OH
H
2,5-Furandicarbaldehyde
Succinic acid O
O
O
HO
OH
2,5-FDCA
O
O
NH2
H2N
HO
2,5-Bis(aminomethyl)tetrahydrofuran
OH
2,5-Dihydroxymethyl furan O HO
OH
2,5-Dihydroxymethyl tetrahydrofuran 1f
Figure 13 FDCA as a platform chemical. Source: Michigan Biotechnology Institute.
tetrahydrofuran and also diamines like 2,5-bis(amino methyl)tetrahydrofuran (Figure 13). • Adipic acid is the most important dicarboxylic acid for the production of polyamides (PAs). The majority of the 2.2 Mio mto of adipic acid produced annually (2006) is used as monomer for the production of PA66 by a polycondensation reaction with hexamethylenediamine (Section 10.04.3.4.1). Adipic acid is currently predominantly produced in a two-step process by oxidation of cyclohexane with cyclohexanol/cyclohexanone (Anol-Anon or KA oil) as intermediate.27b Verdezyne has developed a process to produce adipic acid by a yeast microorganism. Using proprietary tech nologies, Verdezyne discovered and is engineering a metabolic pathway that can utilize sugar, plant-based oil, or alkanes.57 In addition, a new route for the production of adipic acid from glucose has been recently announced by Rennovia. The process includes the catalytic oxidation of glucose to glucaric acid followed by a catalytic reductive dehydroxylation to produce adipic acid.58 • The acid-catalyzed hydrolysis of cellulose as well as the mechanism of enzymatic cellulose biodegradation, the mechanisms of mercerization, and the relationship between the chemical structure of cellulose derivatives and their phy sicochemical and mechanical properties are topics of intense research in order to make cellulosic biomass available for glucose-based white biotechnology and structurally stable biopolymers. In such investigations, methods to synthesize cellulose in a kind of reverse hydrolysis would enable the design of model compounds and control the degree of polymerization and/or depolymerization. Pathways for synthesis of cellulose have been investigated by Schlubach and Lührs59 and later by Nishimura and Nakatsubo.60 The polymerization of glucose derivatives to
produce stereoregular polysaccharides has also been achieved by cationic ring-opening polymerization (ROP) of glucose orthopivalate.61 Starting from substituted glucose monomers, the formation of glucose oligomers, however, is easily achieved. Indeed, APGs result from the Fischer reaction of glucose with a fatty alcohol. The monoalkylated glucose further reacts with free glucose under the same conditions to yield APG.62 APGs are nonionic surfactants combining a vegetable oil-derived fatty alcohol and sugar and thus are completely based on renewable resources.52,63 The glucose oligomer imparts the hydrophilic moiety of the surfactant molecule.
10.04.3 Carbohydrate-Based Polymers 10.04.3.1 10.04.3.1.1
Polyolefins Polyethylene (PE)
PE is by far the most important product made of ethylene chain polymerization. Bio-based PE has exactly the same chemical, physical, and mechanical properties as petrochemical PE. Since the beginning of the new millennium, Brazil has become the bonfire for green PE production using the described value chain (Section 10.04.2.1) sugarcane, bioethanol, bioethylene, bio polyethylene (Braskem, Santelisa Vale/Crystalsev, and Dow).
10.04.3.1.2
Polyvinyl chloride (PVC)
PVC is also obtained by chain polymerization of its monomer, produced from chlorine (57 wt.%, manufactured by the chlor alkali electrolysis of brine yielding chlorine, sodium hydroxide, and hydrogen as coproducts) and ethylene (43 wt.%) via 1.2-dichloroethane. PVC and its precursors are by far the most important value-adding chlorine disposal route. For the production of bio-based PVC, bioethylene is derived from bioethanol. Solvay Indupa has announced plans to produce PVC from partly bio-based feedstock on their manufacturing
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides site in Santo Andre/BR.63a As PE, PVC produced from bio-based ethylene can fully substitute PVC from conventional production.
10.04.3.1.3
Polypropylene (PP)
Bioethylene also opens a gateway to C3 building blocks such as propylene (the second most important organic building block for polymers after ethylene) to be manufactured by enzymebased fermentation. However, the first commercial size plant that has been commissioned by Braskem with a capacity of 30.000 mto polypropylene eventually will dimerize sugar canebased bioethylene to make butylene, and then through metath esis, convert ethylene and butylene into biopropylene.
10.04.3.1.4
C4-derived polymers
Dehydration of bio-based isobutanol opens the value chain to C4 olefins such as isobutene and butadiene and to C4-derived biopolymers. As is well known from cracker-based chemistry, cationic chain polymerization of isobutene yields the homo polymer polyisobutene (PIB), while copolymerization of about 98% isobutene with about 2% isoprene yields butyl rubber. 1,3-Butadiene is homopolymerized by radical or anio nic chain polymerization to yield polybutadiene (BR) or copolymerized with other types of monomers such as styrene and acrylonitrile to yield styrene–butadiene rubbers (SBR) or acrylonitrile–butadiene–styrene (ABS) thermoplastics.
10.04.3.1.5
Polyisoprene
Isoprene, which can be obtained from the C5 platform, is also a high-value hydrocarbon. The immediate precursor to isoprene is isopentenyl diphosphate (IPP). Two biosynthetic routes to IPP have been described.2 Chain polymerization of isoprene leads to polyisoprene (PI) with different configurations; the most important for industrial applications is 1,4-cis-PI. The aim of some research is to synthesize natural rubber (NBR) from IPP. In 2010, collaboration between Genencor and the Goodyear Tire & Rubber Company resulted in a breakthrough technology for tires made from bioisoprene.
10.04.3.2
Thermoplastics Polyesters
10.04.3.2.1
General considerations
• A classification of both linear and cross-linked polymers may be based on the mechanism of the polymerization process. For polyester synthesis, two mechanisms of polymerization, polycondensation (Figure 14) and ROP (Figure 15), can be used: O R1
+ R2 OH
O
Catalyst
OH
R1
+ H2O OR2
Figure 14 Esterification reaction between an acid and a diol. O
O O
O
Initiator Catalyst
O
HO O
Glycolide
Figure 15 An example of ROP of a cyclic monomer.
H
n
71
The polycondensation synthesis of polyesters requires two steps and depending on the use of the diacid or the dimethyl ester of the diacid, two different industrial pro cesses are developed.64 For the first step of the diacid process, the diacid is prepolymerized with an excess of the diol (molar ratio = 1:1.05 to 1:1.2) at high temperature and under pressure. Acid groups are able to catalyze the reaction. Transesterification occurs during the second step, at high temperature and under vacuum to remove the excess of diol by distillation. To achieve high-molar-mass polymers, this step needs catalysts such as metal oxides (antimony, germanium, etc.), alkoxides (titanium, etc.), or acetates (lithium, magnesium, etc.). When the dimethyl ester of the diacid is used in the first step, a catalyst has to be introduced for interexchange reactions. • The ROP is an ionic chain polymerization initiated by strong bases such as metal alkoxides, thioureas, heterocyclic carbenes, or complexes of aluminum, zinc, tin, and lanthanides. Depending on the initiator and reaction condi tions, almost all conceivable mechanisms (cationic, anionic, coordination, etc.) have been proposed to explain the kinetics, side reactions, and nature of the end groups. The ROP allows a higher control of the reaction and remains the widely used method for the synthesis of well-defined materials. Degradation of polyesters is primarily due to hydrolysis of the ester linkages in the presence of water. On the contrary, drying conditions are recommended for processing of com mercial polyesters. When aliphatic polyesters are exposed to a humid environment following drying, moisture is quickly absorbed into the polymer up to its equilibrium level of swelling. Kinetics for melt hydrolysis depends on water con centration, acid or base catalysis, and polymerization catalyst concentration. In fact, many of the aliphatic polyesters can be rendered biodegradable. They are degraded to oligomers and monomers via hydrolysis and then metabolized to car bon dioxide and water. After use, this can be quite a facile process under standard industrial composting conditions, but it is worth noting that degradation is very slow at low temperatures. • Polyesters represent a large group of polymers that can lead to primarily partial substitution or full bio-based polymers. More particularly, aliphatic polyesters have received consid erable attention for applications in packaging, adhesives, coatings, and printing inks as well as in biomedical applica tions, such as resorbable surgical sutures for their favorable features that hydrolytic and/or enzymatic degradation pro ducts can be naturally metabolized into nontoxic substances as they are readily susceptible to biological attack.65 The bio-based aliphatic or cycloaliphatic α,ω-dicarboxylic acids such as succinic, fumaric, malic acids, and FDCA in combination with bio-based diols such as 1,2-PDO (from sorbitol or glycerol), 1,3-PDO (from glycerol, C3 platform); ethanediol (from ethylene, C2 platform), or isosorbide (from dehydration of sorbitol, C6 platform) (Figure 16) create new fully renewable polyesters. Typical monomers for ROP are
72
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
HO
H O
OH HO
OH
H3C
OH
OH
HO
O H
1,2-Propanediol
1,3-Propanediol
OH Isosorbide
1,2-Ethanediol
Figure 16 Formulas of some bio-based diols for polyester synthesis.
O
O
O
O O
O n
O O O
O
Lactide
Glycolide
γ-Butyrolactone Cyclic oligoesters
Figure 17 Typical cyclic monomers for ROP.
lactide, glycolide, γ-butyrolactone, and cyclic oligoesters (Figure 17).
10.04.3.2.2
Polylactide acid and polyglycolic acid
10.04.3.2.2(i) Scheme leading to polymers As described in the introduction, corn or sugar feedstocks are processed to yield D-glucose that is then fermented to yield lactic or glycolic acid. The lactic or glycolic acids can be ther mally and catalytically converted into their cyclic analogs, i.e. polylactic acid (see Chapter 10.12) and polyglycolic acid (PGA) (Figure 18). When a diol is used as initiator, the formed polymers are with terminal hydroxyl groups. 10.04.3.2.2(ii) PLA polymerization To proceed in reasonable conditions and afford polymers with controlled properties, many catalyst systems have been evalu ated for the ROP of lactide.66 Tin compounds, especially tin(II) bis-2-ethylhexanoic acid (tin octoate), are preferred for the bulk polymerization of lactide due to their solubility in molten lactide, high catalytic activity, and low rate of racemization of
the polymer. The ROP of L-lactide using an equimolar complex of 2-ethylhexanoic acid tin(II) salt, Sn(Oct)2, and triphenyl phosphine as catalyst shows a reactivity providing a polymerization propagation rate fast enough to imagine a continuous single-step reactive extrusion process for bulk poly merization.67 For some applications, one solution to the problem is to use biocompatible (i.e., nontoxic) initiators for lactide polymerization.
10.04.3.2.2(iii) PLA properties PLA exists in three isomeric forms: D, L, and racemic (D,L). PLA can be either amorphous or semicrystalline, depending on the stereochemistry and thermal history. For semicrystalline PLAs, both the glass transition temperature (Tg 58 °C) and melting temperature (Tm, 130–230 °C) (depending on structure) are important for determining the use temperatures. Both of these transitions (Tg and Tm) are strongly affected by the overall optical composition, primary structure, thermal history, and molar mass. The crystallization kinetics of PLA is rather low and strongly dependent on the optical copolymer composi tion.68 The slow crystallization rate means that PLA-extruded objects such as sheets and pellets are very often 100% amor phous after normal quenching operations. The cost performance balance of PLA has resulted in its use in many applications, including packaging, paper coat ing, fibers, films, and a host of molded articles. PLA is not being used in these applications solely because of its degradability nor because it is made from renewable resources. PLA can be used for not only short but also long-term applications.
O
OH
HO
O
HO
O
O
Lactic acid
OH
O O
n
High-molar-mass PLA Ring-Opening Polymerization (ROP)
Polycondensation –H2O
O O
HO O
O O n
O
OH Depolymerization O
O
O Lactide
Low-molar-mass PLA Mn ≈ 5000 g mol−1 Figure 18 Different steps for PLA production via prepolymer and lactide. (Same process for PGA via prepolymer and glycolide.)
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
10.04.3.2.2(iv) Polyglycolide PGA is a rigid thermoplastic material and is also produced by ROP of glycolide (the cyclic dimer of glycolic acid). It exhibits a higher crystallinity than does PLA (46–50%). The glass transi tion temperature is Tg 44 °C and the melting temperature is Tm 223 °C.69 PGA is not soluble in most organic solvents but has a high sensitivity to hydrolysis. Compared to PET, PGA displays better barrier properties to CO2 and O2. It can be processed by extrusion, injection, and compression molding, but its processing window between its melting and degradation temperatures is extremely narrow. The attractiveness of PGA as a biopolymer in medical applications is due to the fact that its degradation product, glycolic acid, is a natural metabolite.70
10.04.3.2.3
Aliphatic polyesters: poly(alkylene succinate)s
10.04.3.2.3(i) Polymerization • Poly(alkylene succinate)s can be made through the melt condensation process described above (Figure 14).71 Even in the presence of very effective transesterification catalysts and under high vacuum conditions, the preparation of high molar-mass poly(alkylene succinate)s with improved mechanical and processing properties remains synthetically challenging. A useful way to overcome the problem of incomplete polymerization and short chain length is to use so-called chain extension technology, usually carried out in the presence of coupling agents reacting with the reactive chain ends. Different types of chain extenders can be used: epoxies (reaction with –COOH chain ends), isocyanates, and carbonate or phosgene (reaction with –OH chain ends). • For other applications like coatings, α,ω-dihydroxy-terminated oligo(alkylene succinate)s have been prepared via the thermal polycondensation of excess diol and succinic acid. The molar mass of the products depends on the excess diol used, but as one target is to have liquid macrodiols at low temperature (see Section 10.04.3.3.2), it usually ranges between 900 and 4000 g mol−1. α,ω-Dicarboxy-terminated products have also been prepared using an excess of succinic acid. 10.04.3.2.3(ii) Properties and applications • Aliphatic polyesters have been recognized for their biode gradability and susceptibility to hydrolytic degradation. One of the most investigated biodegradable polyesters is poly (butylene succinate) (PBS). PBS is a flexible polymer (Tg –32 °C and Tm 110 °C) that can compete with PE but with a good printability and a good compatibility with other biodegradable polymers such as PLA or starch. • Initially, PBS was prepared from fossil feedstock, but obtain ing 1,4-BDO from bio-based succinic acid or directly from glucose fermentation would afford 100% bio-based PBS (Mitsubishi).41b • A new 100% bio-based polyester with an odd number of – CH2– groups in its diol monomer could be poly(trimethy lene succinate).72 • For aliphatic polyesters, it is known that chemical structure, molar mass, degree of crystallinity, spherulite size, and lamellar structure can influence the biodegradation rate.
73
Copolymers such as poly(ethylene-co-butylene succinate) or poly(butylene succinate-co-adipate) have lower thermal properties and (because of the lower cristallinity) exhibit higher biodegradation rates than do the homopolymers.72a • The high rigidity of isosorbide, a starch-derived diol, has been extensively exploited to enhance thermomechanical stability of polycondensates, such as polyesters.73 For exam ple, isosorbide-based polysuccinates with glass transition temperature Tg values in an appropriate range (45–65 °C) have been prepared. One advantage of powder coating applications of such fully aliphatic α,ω-hydroxyl- or car boxy-terminated low-molar-mass (2000 and 6000 g mol−1) polyesters is the absence of yellowing of the coating over time.74 However, the major difficulty for the use of isosor bide is still the control of the polyester functionality because of the low reactivity of the secondary hydroxyl group.
10.04.3.2.4
Poly(hydroxyl alkanoates)
10.04.3.2.4(i) Synthesis PHAs are a class of aliphatic polyesters produced via fermenta tion of renewable feedstocks. The main members of the PHA family (Figure 19) are those with x = 1 (for all commercially relevant polymers) and R variable: poly(3-hydroxybutyrate), P(3HB), with R = methyl; poly(3-hydroxyvalerate), P(3HV), with R = ethyl; poly(3-hydroxyhexanoate), P(3HHx), with R = propyl; poly(3-hydroxyoctanoate), P(3HO), with R = pentyl; poly (3-hydroxydecanoate), P(3HD), with R = heptyl; and the medium-chain-length poly(3HOd), with R = 15. Whereas production of PLA or PBS involves a two-stage process (fermentation to monomer followed by a conven tional polymerization step), PHAs are produced directly via fermentation of carbon substrate within the microorganism. Indeed, the PHA accumulates as granules within the cyto plasm of cells and serves as a microbial energy reserve material. However, PHA extraction requires large amounts of organic solvent after the fermentation step, which rises envir onmental and health concerns for industrial production. A wide range of PHA homopolymers, random copolymers, and terpolymers have been produced, in most cases at the labora tory scale.75 10.04.3.2.4(ii) Properties and applications PHA polymers have a semicrystalline structure with a rather high degree of crystallinity ranging from 40 to 80%. P(3HB) homopolymer is a stiff and brittle material. It has a melting temperature (Tm 180 °C) and mechanical properties (Young’s modulus and tensile strength) closed to those of PP. The elongation at break is, however, substantially lower than that of PP. The incorporation of hydroxyalkanoate
O HO
Figure 19 Structures of PHAs.
R H C O H2 x n
74
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
comonomers into a P(3HB) chain can greatly improve the mechanical properties of the material. Due to its high crystallinity (60–70%), P(3HB) displays excellent resistance to solvents and a relative resistance to hydrolytic degradation. It also exhibits good barrier properties. It can be processed as classic thermoplastics and melt spun into fibers, but one difficulty for the processing of films and plates is its low crystallization rate. Like other aliphatic polyesters, i.e., PLA and PBS, PHA has the potential for substitution in conventional applications. PHA is also a promising material for many novel applications including tissue engineering scaffolds, where biodegradability and the use of renewable feedstocks are prerequisites that conventional syn thetic thermoplastic polymers cannot meet.76 PHA technology ultimately goes back to the1970s and ‘80s, when ICI first devel oped Biopol PHA from naturally occurring bacteria. ICI’s patents were first bought by Monsanto and ultimately acquired by Metabolix. Metabolix and ADM in the United States and Kaneka in Japan are actually the front-runners for establishing commercial polyhydroxyalkanoate production.
10.04.3.2.5 Aromatic polyesters: poly(alkylene terephthalate)s 10.04.3.2.5(i) Polymerization Poly(alkylene terephthalate)s can also be made by the melt condensation process previously described. In this case, because of the high melting temperature of these aromatic polymers, solid-state polymerization (SSP) can be used during a third step to achieve high inherent viscosities. The product after the second step is essentially noncrystalline, but it can be made semicrystalline by heating the pellets to a temperature above the Tg for an extended period of time. This induces crystallization so that the polyester can then be heated to a higher temperature but below the melting temperature Tm to raise the molar mass during this third step. SSP is also a method suitable for the preparation of copolymers from polyconden sates with the retention of long homopolymer blocks. 10.04.3.2.5(ii) Properties and applications • Partially bio-based poly(trimethylene terephthalate) (PTT) produced from petrochemical terephthalic acid (or dimethyl terephthalate) in combination with bio-based 1,3-PDO (DuPont, USA) has Tg 55–70 °C and a Tm 225–228 °C, lower than the ones of poly(ethylene terephthalate) (PET). It can be said that PTT combines physical properties similar to PET (strength, stiffness, toughness, and heat resistance) with processing properties of poly(butylene terephthalate) (PBT) (low melt and mold temperatures, rapid crystallization, and faster cycle time compared to PET); it is also similar to PAs (PA6 and 6,6) and PP for fiber applications and is similar to polycarbonate (PC) for molding applications. In addition, PTT films have excellent barrier properties to carbon dioxide and water vapor compared to PET and PA films. • Once bio-based ethanediol and BDO (from succinic acid hydrogenation or from glucose fermentation) are available in sufficient quantities, it will also be possible to produce partially bio-based PET and PBT. • As explained before, the use of isosorbide offers enhanced material properties. Copolyesters of ethanediol, isosorbide,
and terephthalic acid (PEIT) have a higher glass transition temperature compared to PET and can therefore broaden the range of applications. Depending on the isosorbide content, amorphous PEIT copolyesters can have Tg 120–140 °C and can compete with other amorphous thermoplastics such as polyethylene terephtalate glycol (PETG), PC, PMMA, etc.73,77
10.04.3.2.6
Emerging polyesters
1. Poly(alkylene adipate)s are certainly the most common ali phatic polyesters. Bio-based poly(alkylene adipate) oligomers and polymers with the same properties are expected to be produced when the bio-based adipic acid is an industrial product.57,58 2. Polyesters based on FDCA.78–80 Aliphatic FDCA has a large potential as a replacement for aromatic terephthalic acid, a widely used component in various polyesters, PET, PEIT, PBT and PTT as explained above. An optimized process for the synthesis of FDCA monomer and for the production of polyesters with high molar masses and low coloration has been developed by Avantium, a spin-off from Royal Dutch Shell in 2010. 3. Poly(γ-butyrolactone). γ-Butyrolactone can be polymerized by ROP. Work has to be done to determine if the obtained α,ω-hydroxyl-terminated oligomers and high-molar-mass polymers can be used instead of petro-based poly (ε-caprolactone). 4. Poly(malic acid). Biodegradable malic acid-based polymers are interesting alternatives for biomedical and pharmaceuti cal applications such as polymeric matrices for drug delivery systems. Poly(malic acid) (PMA) has been reported to be synthesized by two approaches: ROP and direct polyconden sation. The ROP route is difficult because of the several steps involved (synthesis and then ROP of benzyl β-malolacto nate); in contrast, direct polycondensation is a very useful method for the synthesis of PMA with high molar masses.81
10.04.3.3 10.04.3.3.1
Polyurethanes (PUs) and Polyureas General considerations
The mechanism for isocyanate reactions consists in the nucleo philic addition of an active hydrogen (AH) compound to the electron-poor carbonyl atom of isocyanate (Figure 20). A broad range of hydrogen-containing nucleophiles react with both aromatic and aliphatic isocyanates. Reaction with poly alcohols gives PUs (–O–CO–NH–), while reaction with amines gives polyureas (–NH–CO–NH–). If the functionality of the hydroxy-containing compounds or the isocyanate is increased beyond 2, branched and possibly cross-linked polymers are produced.82 Because the nature of the polyol and isocyanate components can widely vary, PUs _
R
N C O + AH
O R N C+ A H
O R HN C A
Figure 20 Mechanism for isocyanate reaction with an AH compound.
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
are among the most versatile polymers producing a wide variety of materials (see Chapter 10.24). PU foams are prepared from basically the same raw materi als as elastomers. Instead of the chain extender, water is used, which reacts with isocyanates to form an amine and CO2, which results in foaming. The diamine thus created can then react with isocyanate groups, giving polyurea short segments.
10.04.3.3.2
Bio-based PUs
• So far, the isocyanate component (with the exception of one vegetable oil-derived fatty dimer diisocyanate) is exclusively derived from petrochemical feedstock. However, there are some results in the literature on the use of a furanic diiso cyanate monomer, derived from HMF.83 1,4-Butane diisocyanate (from C4 platform) has been used as building block for biomedical biocompatible PUs.84 • On the contrary, there are a lot of bio-based macrodiols, but most of them are from vegetable oil such as soybean oil, castor oil, sunflower oil, rapeseed oil, and their fatty acids (see Chapter 10.03). Other bio-based polyester macrodiols from carbohydrate feedstock such as α,ω-diol PBS, poly(butylene adipate) and copolymers, poly(alkylene-co isosorbide succinates), and poly(γ-butyrolactone) have been discussed in Section 10.04.3.2.3. • For polyether macrodiol, polyethylene oxide, polypropylene oxide and copolymers obtained by anionic polymerization of EO and propylene oxide, polytetrahydrofuran obtained by cationic polymerization, and also polytrimethylene ether obtained from 1,3-PDO (Cerenol™, DuPont) can be used as soft segments. Sucrose, sorbitol, and their derivatives have been used for a long time as short-chain polyether polyols for rigid foams. Physicochemical properties of the PU foams are improved when sucrose with its eight hydroxyl groups is first alkoxylated with ethylene or propylene oxide and the resulting polyether polyols are used for PU formation.85 • For chain extenders used for linear segmented PU synthesis, all the bio-based diols described for synthesis (Section 10.04.3.2.1) such as BDO, 1,2- and 1,3-PDOs, and isosorbide can be used.
10.04.3.4
Emerging Products
10.04.3.4.1
Bio-based polyamides (PAs)
1. Formation of amide linkages: –CONH– As for polyesters, two pathways, polycondensation (step-growth polymerization with water as side product, Figure 21) and ROP, can be used for PA synthesis. The different PAs are identified by numbers denoting the number of carbon atoms in the monomers (diamine first for the diamine + diacid, A2B2 type).
O
O R1
OH
+ R2 – NH 2
R1
NHR2
Figure 21 Reaction between an acid and a diamine.
+ H2O
75
2. No bio-based PAs from carbohydrate feedstock are commer cially produced at the present time, but some may emerge by using the following: • diacids previously described for the synthesis of bio-based polyesters synthesis; • diamines such as 1,4-butane diamine (obtained from succinic acid) or 2,5-bis(aminomethyl)tetrahydrofuran (prepared from FDCA, Figure 13); • caprolactam, the monomer for PA6, which may be pro duced in future by fermentation from glucose, via the precursor lysine;86 • the reaction of glutaric acid and a diamine that would lead to polyhydroxypolyamide but with unknown properties. 3. Expected properties for these new PA: • PA44 based on 1,4-butane diamine and succinic acid, PA4n based on 1,4-butane diamine, and PAn4 based on succinic acid have been manufactured on the laboratory scale.33b These PAs show interesting and unexpected properties. For example, PA24 possesses the same properties as both silk proteins and commercial PAs. PA46 (Stanyl®) with a melting point of 280 °C is a commercial product from DSM; • The properties of polyesters can be improved by the intro duction of amide groups into the main chain; poly(ester amide)s based on succinic acid, BDO, and 1,4-butanediamine can be synthesized for biodegradable properties; • Polyaspartates (from the L-aspartic acid chemistry) are acidic PAs and have been commercialized by Bayer.87
10.04.3.4.2
Multisegmented block copolymers/TPEs
Aiming at generating materials exhibiting properties similar to linear segmented PUs and by using polyesters or PA chemis tries, multisegmented polyether–ester (PE-b-E) and polyether– amide (PE-b-A) have been prepared. They are proposed for automotive, shoe, medical, and wire and cable applications. DuPont has made thermoplastic polyester elastomers con taining 20–37% b.w of bio-based material by using a polyol, CerenolTM (produced by direct polymerization of bio-based 1,3-PDO), as elastomeric soft segment instead of the classical polytetrahydrofuran macrodiol. Partially bio-based thermo plastic PA elastomers from Arkema with PA11 hard segments are available and it is easy to imagine a 100% bio-based poly ether–amide by the use of the soft Cerenol polyether segment with PA11 as rigid segment.
10.04.3.4.3
(Meth)acrylic acid and (meth)acrylate families
1. Poly(meth)acrylic acid and poly(meth)acrylates are an important family of polymers for a lot of applications, such as paints, coatings, or ‘acrylic glass’. Polymers are obtained by free-radical chain polymerization of (meth) acrylic acid or (meth)acrylate monomers. As all the (meth) acrylates monomers can be prepared from (meth)acrylic
76
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
acids, the main point is the preparation of bio-based (meth) acrylic acid. 2. Acrylic acid can be obtained from 3-HPA platform chemi cals through fermentation (via dehydration) or from levulinic acid or glycerol building blocks.
PC is produced via the phosgene process, where CO and chlorine are combined to form phosgene (carbonyl dichlor ide, COCl2). Recently, the development and industrialization of a novel process for producing high-quality PC using CO2 as starting material without using highly toxic phosgene has been proposed.91 BPA polycarbonate is a versatile, tough plastic used for a variety of applications, from bulletproof windows to com pact discs (CDs) or eyeglasses. It can crystallize, but in practice it is an amorphous thermoplastic with a Tg 150 °C that flows above about 300 °C. Injection mold ing is more difficult than other common thermoplastics owing to its non-Newtonian flow behavior. The main advan tage of PC over other types of thermoplastic is unbeatable strength combined with light weight, excellent transparency, durability, and rather high refractive index (1.60). However, it exhibits poor solvent resistance and low scratch resistance. • Poly(aliphatic carbonate)s display promising characteristics; they have a better biodegradability than does the aromatic PC and could be employed to develop specialty thermoplas tics or polycarbonate diols (PCDL) as soft segments in PU elastomers: – PCDL prepared via the transesterification of alkylene car bonates with aliphatic diols such as 1,6-hexanediol are hydroxy terminated and typically possess molar masses in the range of 1000–5000 g mol−1 (Figure 22(a)).92 The
A newly discovered enzyme makes it possible to turn a linear C4 carbon structure into a branched one. Compounds of this type are precursors of methyl methacrylate monomer.88 Recently, biomass-based monomer precursors of poly (methacrylic acid) (PMA) and PMMA were reported to be obtained from the thermal degradation of a bio-based poly (tetramethylene glycolide) (PTMG).89 Also known as methyl succinic acid, itaconic acid (Figures 2 and 4(d)) is a five-carbon dicarboxylic acid. It is currently produced by fermentation of glucose or saccharose and is used as a specialty monomer. Itaconic acid is frequently used as comonomer in vinyl and acrylic latex recipes to improve colloidal stability.90
10.04.3.4.4
Polycarbonates
10.04.3.4.4(i) General considerations • Polycarbonates with –OCO2– linkage can be divided into poly(aromatic carbonate)s and poly(aliphatic carbonate)s. An aromatic PC based on 2,2-bis(4-hydroxyphenyl)propane (commonly called bisphenol A, BPA) and usually abbre viated as PC is the most widely used engineering thermoplastic in various applications. The vast majority of
(a)
O
(n + 1) HO R OH
+ n H3CO
O OCH3
HO
O
R
O R
OH + 2n CH3OH n
(b)
R
R
O ROP
n O
O
H
O
O R
O
OH R
R
R
n–1
O
R = H, CH3
(c)
O O
O O
LIPASE
O
O
70 °C, bulk
(d)
O
O + CO2
CHO
n Poly(TMC)
Trimethylene carbonate (TMC)
O
lonic lnitiator Catalyst
O n Poly(cyclohexene carbonate) PCHC
Figure 22 Different routes to the synthesis of aliphatic PCs: (a) transesterification of alkylene carbonates with aliphatic diols; (b) classic ROP of cyclic carbonates; (c) ROP of cyclic carbonates with the help of a lipase; and (d) alternating copolymerization of epoxides with carbon dioxide (CO2).
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
main advantage of PUs containing oligocarbonate soft segments is their higher hydrolytic stability than that of conventional polyester-based PUs (the hydrolysis of car bonate linkages does not produce the acidic groups that catalyze the hydrolytic degradation of ester bonds). – Another route for aliphatic PC synthesis is the ROP of cyclic carbonates by a base catalyst (Figures 22(b) and 22(c)). One side reaction is decarboxylation and as a consequence, the formation of ether linkages.93 It can be limited by the choice of a selective catalyst. – The last synthesis method is the alternating copolymeriza tion of epoxides, such as propylene oxide, with carbon dioxide (CO2) (Figure 22(d)). The CO2/epoxy copolymer synthesis, which is one of the most promising processes for CO2 utilization, can use propylene oxide from glycerol. The reaction needs an ionic initiator, but owing to the kinetic stability of carbon dioxide, it also requires the use of a cocatalyst.94 The CO2/propylene oxide copolymer has interesting properties: the copolymer burns gently in air without emitting toxic volatiles, it adheres strongly to a cellulosic substrate, and the barrier properties for O2 and water are rather good. Commercial products are from Novomer and recently from Bayer. Unfortunately, the scope of this polymer is presently limited by its low Tg 40 °C. A higher Tg is required to allow the use of these CO2 base alternating copolymers as structural mate rials. It explains the use of cyclohexene oxide (Tg of the copolymer 115 °C) instead of propylene oxide. 10.04.3.4.4(ii) Bio-based PCs While most of used PCs are derived from petroleum, the con version to bio-based PC is certainly reachable: • Trimethylene carbonate (TMC), a cyclic monomer, can indeed be obtained by reacting diethyl carbonate with bio-based 1,3-PDO and then polymerizing by ROP of TMC in the presence of diethyl zinc or triethyl aluminum or lipases.95 • Transesterification of alkylene carbonates can be carried out in the melt with isosorbide or 1,3-PDO and a catalyst to obtain bio-based aliphatic PCs.96 • But the more important bio-based engineering thermoplastic is certainly the isosorbide-based bio-PC proposed by Mitsubishi Chem (2010). This new biopolymer is produced without solvent by melt transesterification process and pre sents the advantage of low energy consumption. Compared to BPA-PC and PMMA, it shows high transparency, extremely good UV light resistance and very unique optical properties and low birefringence, relatively good heat (Tg 130 °C), and multiaxial impact resistance.97 Several patents from other companies have been published in 2010, which con firm that this polymer has attractive properties.98
10.04.3.4.5
Furan resins
In the presence of an acid catalyst (such as a mineral acid or BF3), furfuryl alcohol (formula in Figure 9) undergoes
77
autocondensation (methylolation) to produce liquid linear oligomers consisting of furan rings linked by methylene bridges. The chemistry and applications of furan resins are well known and have even lost market volume at the end of the last century. They are primarily employed for foundry sand cores and molds for casting metal parts. There are still some commercial products such as BioRez resin from TransFurans Chemicals. Recently, it was shown that linear oligomers of furan could be used as organic semiconductors with field effect mobilities similar to those of the corresponding thiophene analogs.99
10.04.3.4.6
Unsaturated polyesters, UP thermosetting resins
10.04.3.4.6(i) Thermosetting polyesters Network formation distinguishes polyester resins from linear (thermoplastic) polyesters such as those in Section 10.04.3.2 (PBS, PBT, PET, etc.). Cross-linking can be achieved by use of polyols such as glycerol, as in the case of saturated polyesters named glyptal. Glyptal, which is used mainly as an adhesive or modified with natural or synthetic oils (oil-modified alkyds) for coatings, is formed by the reaction of glycerol and phthalic anhydride. But most of cross-linked polyesters are obtained from unsaturated polyester precursors. When an excess of maleic anhydride or a mixture of maleic anhydride and other anhydride (particularly phthalic anhy dride) or unsaturated diacids (like fumaric acid) are reacted with aliphatic diols, low-molar-mass UPs are formed. Products having molar masses around 1000–2000 g mol−1 are generally diluted with a liquid vinyl monomer, most often styrene. Such a reactive mixture called ‘UP resin’ can be transformed into cross-linked polymers through a free-radical chain copolymer ization between the styrene and the maleate/fumarate double bonds. Cured UP resins are rigid materials used as matrices for glass fiber composites; the products are called sheet or bulk molding compounds (SMCs or BMCs).82 Another family of an UP resin called vinyl-ester, VE resins is obtained through the reaction of an epoxy monomer with methacrylic acid or the reaction of an isocyanate oligomer with hydroxylethyl methacrylate. These VE resins are also dis solved in styrene. 10.04.3.4.6(ii) Bio-based UP prepolymers As the aim is to prepare bio-based UP prepolymers, all the diacids and diols previously described (Section 10.04.3.2.4) can be used. Rigid phthalic anhydride units can be replaced by FDCA or by the use of a rigid diol like isosorbide. Since the generation of UP resins also needs double bonds on the back bone, fumaric acid and itaconic acid have been proposed.100 For VE prepolymers, the bio-based epoxy backbones are discussed in the next section and for PUs, backbones are dis cussed in Section 10.04.3.3.2. 10.04.3.4.6(iii) Bio-based reactive diluents As said, UP or VE prepolymers are dissolved in a reactive diluent such as styrene. Since the commercial inception of UP resins, styrene has been a primary reactive diluent due to its low cost, availability, ease of use, and resulting excellent mechan ical properties. However, in recent years, government regulations have restricted styrene emissions in open molding facilities due to harmful environmental and health effects. Accordingly, in addition to renewable (or recycled) raw
78
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
CH3 O
O O
CH3
CH3
OH
O
O
O CH3
n
Figure 23 Formula of DGEBA with different degrees of polymerization, n.
materials, the UP resin industry has a need to offer styrene-free and volatile organic compound (VOC)-free UP resins. Different dimethacrylate monomers of BDO or 1,3-PDO (which could be bio-based) and itaconate esters have been tested with some success.101
10.04.3.4.7
Thermosetting epoxy resins
Cross-linked epoxies exhibit outstanding properties that have placed them as the standard option for a variety of applications such as adhesives, paints, coatings, and composites for struc tural applications.82 A major type of epoxy monomers is derived from the reaction of bis(4-hydroxy phenylene) 2,2-propane (called BPA) and 1-chloropropene 2-oxide (called epichlorohydrin) in the presence of sodium hydroxide (con densation reaction). The structure of the major product, diglycidyl ether of bisphenol A (DGEBA), and its condensed forms (Figure 23) is dependent upon the stoichiometry of the reaction. Amines are the most commonly used curing agents/hard eners for epoxides. The polyaddition reaction involves epoxy groups reacting with primary and secondary amines. One epoxy ring reacts with each amino proton. The epoxy–phenol reaction needs to be activated by some catalysts such as imida zole. The epoxy–acid reaction proceeds through a more complex polyaddition mechanism with some side reactions (transreaction and acid–alcohol reactions). But epoxy monomers are very versatile molecules and they can react with both nucleophilic and electrophilic species. Thus, both Lewis acids and bases are able to initiate the ionic chain polymerization of epoxy precursors. The chain polymer ization of difunctional epoxy monomers leads to networks. They can also copolymerize with cyclic anhydrides, initiated by Lewis bases. After the amines, acid anhydrides constitute the next most commonly used reagents for curing epoxy monomers.
prepolymers have been prepared and tested.102,103,104 Another route is the enzymatic epoxidation of cardanol.105 However, “bio-phenol” is a still missing building block and more generally, modified aromatic-based epoxy prepolymers would be desirable because of the classification of BPA as CMR R3 substance, even more so, as the discussion around the endocrine potential of BPA has entered the greater public. 4,4-bis-(4’-hydroxyphenyl)pentanoic acid can be a candidate. Also called diphenolic acid, DPA is prepared by the reaction of levulinic acid with two molecules of phenol. Levulinic acid is believed to be a cheap platform chemical and can be commer cially produced from cellulose-rich biomass (especially from waste biomass) in large scale.2,106 It may be a direct replace ment for BPA not only in epoxy resins but also polycarbonates, polyarylates and other polymers. It contains a carboxyl group, absent from BPA, which confers an additional functionality that could be useful in polymer synthesis. Another route, i.e. using natural polyphenols, and more specifically con densed tannins that can be extracted from wastes produced by the wood and wine industries and their molecular subunits such as catechin, resorcinol and/or 4-methylcatechol offers other possibilities.107 10.04.3.4.7(ii) Bio-based hardeners Bio-based diamines, diacids, and acid anhydrides have been discussed in previous section. New bio-based multifunctional amines can be also prepared by degradation of chitosan. Aromatic diamines are used in formulations for structural composites; their replacement by bio-based hardeners can be a problem, which can be solved eventually by the use of bio-based phenols from lignin or by phenalkamines from cardanol.103a,104
10.04.4 Conclusions 10.04.4.1
10.04.3.4.7(i) Bio-based epoxy monomers There is not yet an easy access at the horizon to the production of epoxy monomers from renewable resources. Nonetheless, a significant carbon food-print reduction (30 wt. %) can be expected when using epichlorhydrin, ECH generated from bio-based glycerol (Epicerol® - process, Solvay; GTE-process, DOW) and bio-acetone (which can be industrially produced through the anaerobic fermentation of corn by the Acetone Butanol Ethanol fermentation (ABE process) using the Weizman Organism Clostridium acetobutylicum, ATCC 824). Nevertheless, by reacting epichlorohydrin with sorbitol (com mercial products from Nagase ChemteX or JSI Co), isosorbide, phenols extracted from lignin, or by one pot reaction of furfural with trimethylsulfonium iodide in a basic aqueous medium leading to 2-furyloxirane, new 100% biobased epoxy
Specificity of Bio-Based Polymers
Some of the polymers discussed in this chapter are already produced at large-scale facilities or their industrial productions have been announced. Other polymers need some technical breakthrough development before being produced in the next few years. Difficulties can come from technical challenges. One concerns the polymerization methods. As mentioned in this chapter, most of the carbohydrate bio-based polymers are pre pared by polycondensation. Because transparent and colorless bio-based materials are highly desirable for a lot of applica tions, polymer synthesis must be performed at low temperature, which requires the development of very active catalysts. Another technical challenge is that most of the carbo hydrate bio-based polymers (except polyolefins) are generally more thermally, chemically, hydrolytically, and oxidatively sensitive as compared to petrochemical-derived materials. For
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
O O
O
O
O
O Diglycidyl ether of isosorbide O
O
O
O O
O
O O
O
O
O
HO
R
O O
H
O O
O O
O R
OH
O
O
O Diester for plastisizing of PVC and other polymers
H
N H
O
O
Isosorbide
O
n
Polycarbonate of isosorbide
n Aliphatic polyester:
poly(isosorbide succinate)
79
O
O
N H
O O
n Polyurethane with isosorbide as chain extender
O O
O O O
O O n Aromatic polyester: polyethylene-co-isosorbide terephtalate
Figure 24 Different uses of isosorbide (the diisocyanates based on isosorbide are missing).
this reason, one central challenge in their utilization is that they need to be totally reformulated and the processing industry also has to take care of experimental processing conditions.
10.04.4.2
Commodity and Engineered Materials
At the present time, polymers based on renewable materials have found extensive use in the packaging sector, but these materials in the future are expected to increasingly emerge in more components for high-performance applications. Economic difficulties can be overcome more easily when the bio-based precursor converts to the resulting materials with high Tg, optical properties, nontoxicity, and so on. And if so, it is not surprising that the bio-based monomer will rapidly find a lot of applications, as summarized in Figure 24 for the case of isosorbide.73,104,108 In this context, bio-based succinic acid and derivatives and also furan derivatives undoubtedly show great promise in industrial developments.
10.04.4.3
to improve some properties such as the gas barrier of PLA films and also to maintain the stiffness and tensile modulus of toughened polylactide.68 Other examples have been given for epoxy networks in Reference 103. • While carbon dioxide is not plant derived, the direct utiliza tion of this molecule as a C1 source and for the production of polymers could be critically important, given its widespread abundance. The use of CO2 as a monomer in polymer synth esis is not new (aliphatic PC, Section 10.04.3.4.4). But more important seems the fact that recent publications propose the direct synthesis of a monomer like isoprene through the basic equation of photosynthesis: CO2 + H2O and light and with the help of bacteria.109 The final conclusion has to be optimistic: with the help of ‘White biotechnology’,110 macromolecular chemistry, and materials science, polymers from renewable resources and especially the ones coming from carbohydrate chemistry will play an ever increasing role in our life.
Future of Polymers from Renewable Resources
The future of polymers from renewable resources can be stated in two additional points: • The development of nanotechnology offers new opportu nities to improve bio-based polymer properties. For example, a number of researchers have developed polylactide-based nanocomposite materials: PLA/organically modified layered silicate nanocomposites by melt extrusion
References 1. (a) Wolf, O., Ed. Report of the Institute for Prospective Technological Studies: Techno-Economic Feasibility of Large-Scale Production of Bio-Based Polymers, European Commission reference EUR 22103 EN, 2005. (b) Werpy, T.; Petersen, G., Eds. Top Value Added Chemicals from Biomass: Vol. 1—Results of Screening for Potential Candidate from Sugars and Synthesis Gas, US Department of Energy, Office of Scientific and Technical Information, National Renewable Energy Laboratory No. DOE/GO-102004-1992, 2004. www.osti.gov/bridge. (c) Patel, M.; Crank, M.;
80
2. 3. 4. 5. 6.
7. 8. 9. 10.
11. 12. 13. 14. 15. 16. 17. 18.
19.
20. 21.
22.
23.
24. 25. 26. 27.
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
Dornburg, V.; et al. 5th European BREW Final Report: Medium and Long-Term Opportunities and Risks of the Biotechnological Production of Bulk Chemicals from Renewable Resources – The Potential of White Biotechnology; European Commission’s GROWTH Program, 2006. (d) Kamm, B.; Kamm, M. Adv. Biochem. Eng. Biotechnol. 2007, 105, 175. (e) Shen, L.; Haufe, J.; Patel, M. K. Product Overview and Market Projection of Emerging Bio-Based Plastics, Commissioned by European Polysaccharide Network of Excellence and European Bioplastics; Final report June 2009. (f) U.S. Biobased Products: Market Potential and Projections Through 2025. www.usda.gov/oce/reports/energy/index.htm, 2008. (g) Belgacem, M. N.; Gandini, A., Eds. Monomers, Polymers and Composites from Renewable Resources; Elsevier: Amsterdam, The Netherlands, 2008. (h) Gandini, A. Macromolecules 2008, 41 (24), 9491. Bozell, J. J.; Petersen, G. R. Green Chem. 2010, 12, 539. Morschbacker, A. Polym. Rev. 2009, 49 (2), 79. Dinjus, R.; Arnold, U.; Dahmen, N.; et al. In Sustainable Solutions for Modern Economies; Höfer, R., Ed.; RSC Publication: Cambridge, UK, 2009. Bigorra, J.; Höfer, R. Comunicaciones; 38 Jornadas CED: Barcelona, Spain, 2008; p 179. (a) Zaldivar, J.; Nielsen, J.; Olsson, L. Appl. Microbiol. Biotechnol. 2001, 56, 17. (b) Martínez, A. T.; Ruiz-Dueñas, F. J.; Martínez, M. J.; et al. Curr. Opin. Biotechnol. 2009, 20, 348. (c) Kazmi, A.; Kamm, B.; Henke, S.; et al. In Introduction to Advanced Oil Crop Biorefineries; A. Kazmi Ed.; RSC Publications: Cambridge, UK; 2012, pp 1–47. (a) de Vasconcelos, J. N.; Lopes, C. E.; De França, F. P. Braz. J. Chem. Eng. 2004, 21 (3), 357. (b) Ochoa Cáceres, S. M. Dissertation, TU Berlin, 2010. Berg, C. World Ethanol Production and Trade to 2000 and Beyond. http://www. distill.com/berg/ (accessed August 10, 2010). Kochar, N. K.; Merims, R.; Padia, A. S. Chem. Eng. Prog. 1981, 66, 66–70. (a) Le Van Mao, R.; Nguyen, T. M.; McLaughlin, G. P. Appl. Catal. 1989, 48, 265. (b) Le Van Mao, R.; Dao, L. H. U.S. Patent 4,698,452, 1986 (Institut National de la Recherche Scientifique, Sainte-Foy/CA). Bia, J.; Guo, X.; Liua, M.; et al. Catal. Today 2010, 149 (1–2), 143. Chen, G.; Li, S.; Jiao, F.; Yuan, Q. Catal. Today 2007, 125 (1–2), 111. Bronnenmeier, K. From Fossil-To Bio-Based Refineries. http://www.biorefinica.de/ Vortrag%20Bronnenmeier.pdf (accessed September 12, 2010). John, R. P.; Nampoothiri, K. M.; Pandey, A. Appl. Microbiol. Biotechnol. 2007, 74, 524. Hause, B.; Rajgarhia, V.; Suominen, P. WO 2003/102152 (Cargill)., Dec. 2003, Burch, R. R.; Laffend, L. A.; Nagarajan, V.; Nakamura, C. U.S. Patent 7,169,588, 2007 (DuPont). Soucaille, P. WO 2008/052595 (Metabolic Explorer), May 2008. (a) Olivier, F.; Rousseaux P.; WO 2009/068110, 2009 (Metabolic Explorer). (b) Kurian, J. V. A New Polymer Platform for the Future – Sorona® from Corn Derived 1,3-Propanediol. J. Polym. Environ. 2005, 13 (2), 159–167. (c) Tao, J.; Kazlauskas, R., (Eds.) Biocatalysis for Green Chemistry and Chemical Process Development, John Wiley & Sons, Hoboken, 2011. (a) Werpy, T.; Frye, J. G., Jr.; Zacher, A. H.; Miller, D. J. WO 03/035582, 2000 (Batelle). (b) Chaminand, J.; Djacovitch, L.; Gallezot, P.; et al. Green Chem. 2004, 6, 359. Voelker, F.; Figge R.; Soucaille P.; WO 2010/51849 (Metabolic Explorer). May 2010. (a) Donaldson, G. K.; Eliot, A.C.; Flint, D.; et al. WO 2007/050671, 2006 (DuPont). (b) Peters, M.W.; Meinhold, P.; Buelter, T.; Landwehr, M. WO 2008/013996, 2007 (Gevo). (c) Atsumi, S.; Hanai, T.; Liao, J. C. Nature 2008, 451, 86–89. (d) Peters, M.; Liao, J. C.; Atsumi, S.; et al. WO 2008/098227, 2008 (Univers. California). (e) Evanko, W. A.; Eyal, A. M.; Glassner, D. A.; et al. WO 2009/086391, 2008 (Gevo). (f) Buelter, T.; Meinhold, P.; Feldman, R. M. R.; et al. WO 2010/ 051527, 2009 (Gevo/CIT). (a) Nimcevic, D.; Gapes, J. R. J. Mol. Microbiol. Biotechnol. 2000, 2 (1), 15–20; (b) De Guzman, D., http://www.icis.com/blogs/green-chemicals/2011/07/cathay industrial-biotech-file.html (retrieved 20.01.2012); (c) De Guzman, D. http://www.icis.com/Articles/2011/12/05/9513406/green-chemicals-growing number-of-chemical-firms-enter-bio-butanol.html (retrieved 20.01.2012) (a) Ramey, D. E. US Patent 5,753,474, 1996 (Environmental Energy); (b) Kraemer, K.; Harwardt, A.; Bronneberg, R.; Marquardt, W. In 20th European Symposium on Computer Aided Process Engineering – ESCAPE20; Pierucci, S., Buzzi-Ferraris, G., Eds.; Elsevier: Oxford, 2010. Peters, M.; Taylor, J.; Henton, D. E.; Manzer, L. E. WO 2010/099201, 2009 (Gevo). Smith, K. M.; Cho, K.-M.; Liao, C. Appl. Microbiol. Biotechnol. 2010, 87 (3), 1045. West, R. M.; Braden, D. J.; Dumesic, J. A. J. Catal. 2009, 262 (1), 134–143. (a) Chauvel, A.; Lefebvre, G. Petrochemical Processes; Institut Français du Pétrole/ Technip: Houston, TX, 1989. (b) Weissermel, K.; Arpe, H.-J. Industrial Organic Chemistry; Wiley: Hoboken, NJ, 1997.
28. Marliere, P. WO 2010/001078, 2010 (Global Bioenergies). 29. Lohbeck, K.; Haferkorn, H.; Fuhrmann, W.; Fedtke, N. Ullmann’s Encyclopedia of Industrial Chemistry; VCH: Weinheim, Germany, 1990; Vol. A16, p 53. (b) Haddad, M. S. U.S. Patent 6,103,935, 1999 (BP Amoco). 30. Ningjun, C.; Jianxin, D.; Gong, C. S.; Tsao, T. Appl. Environ. Microbiol. 1996, 62 (8), 2926. 31. Zeikus, J. G.; Jain, M. K.; Elenkovan, P. Appl. Microbiol. Biotechnol. 1999, 51 (5), 545. 32. Lee, S. Y.; Lee, P. C.; Hong, S. H.; Chang, H. N. Appl. Microbiol. Biotechnol. 2002, 58, 663. 33. Song, H.; Lee, S. Y. Enzyme Microb. Technol. 2006, 39, 352. (b) Bechthold, I.; Bretz, K.; Kabasci, S.; et al. Chem. Eng. Technol. 2008, 31 (5), 647. (c) Cukalovic, A.; Stevens, C. V. Biofuels Bioprod. Bioref. 2008, 2, 505. 34. Stokes, J. L. J. Bacteriol. 1949, 57, 147. 35. (a) Donelly, M.; Millard, C. S.; Stols, L. U.S. Patent 5,770,435, 1995 (Univers. Chicago). (b) Sanville-Millard, C.; Chao, Y.-P.; Liao, J. C.; Donelly M. Appl. Environ. Microbiol. 1996, 62 (5), 1808. (c) Nghiem, N. P.; Donelly, M.; Millard, C. S.; Stols, L. WO 98/33930, 1997 (Lockheed Martin Energy Res./Univ. Chicago). (d) Nghiem, N. P.; Donelly, M.; Millard, C. S.; Stols, L. EP 1,012,323, 1998 (Batelle/Univ. Chicago Argonne). (e) Donnelly, M. I.; Sanville-Millard, C.; Chatterjee, R. U.S. Patent 6,159,738, 1998 (Univ. Chicago). (f) Nghiem, N. P.; Donnelly, M.; Sanville-Millard, C. Y. WO 2004/043881, 2002 (Batelle). (g) San, K. -Y., Bennett, G. N.; Sanchez, A. U.S. Patent 2005/0042736, 2004 (Rice Univ.). (h) Sánchez, A. M.; Bennett, G. N.; San, K.-Y. Metab. Eng. 2005, 7 (3), 229. (i) Shanmugam, K. T.; O’Neil, L.; Patel, A.; et al. U.S. Patent 2005/0250192 (Univ. of Florida). (j) San, K. Y.; Bennett, G. N.; Sánchez, A. U.S. Patent 7,223,567, 2006 (Rice Univ.). (k) Dehey, F.; Segueilha, L.; Calande, O.; Varlamoff, C. WO 2009/081012, 2008 (Roquette). (l) Caulier, B.; Segueilha, L. WO 2010/092304, 2010 (Roquette). 36. Roa Engel, C. A.; Straathof, A. J. J.; Zijlmans, T. W.; et al. Appl. Microbiol. Biotechnol. 2008, 78 (3), 379. 37. Datta, R.; Glassner, D. A.; Jain, M. K.;Vick Roy, R. U.S. Patent 5,168,055, 1989 (Michigan Biotech./Emerald Bioagriculture/CPC Internat.). 38. Hong, Y. K.; Hong, W. H.; Chang, H. N. Biotechnol. Lett. 2000, 22, 871. (b) Jun, Y.-S.; Lee, E. Z.; Huha, Y. S.; et al. Biochem. Eng. J. 2007, 36, 8. 39. Orjuela, A.; Yanez, A. J.; Vu, D. T.; et al. Fluid Phase Equilib. 2010, 290, 63. 40. (a) Jansen, M.; Verwaal, R. WO 2010/003728, 2010 (DSM). (b) van den Tweel, W. Speciality Chem. Mag. Nov. 2010, 30. 41. (a) Schnabel, R.; Weitz, H. -M. EP 169,396, 1985 (BASF). (b) Gosch, H.-J.; Rust, H.; Fischer, R.; et al. EP 0557786, 1993 (BASF). (c) Burk, M. J.; Van Dien, S. J.; Burgard, A.; Niu, W. WO 2008/115840 A2, 2008 (Genomatica). 42. Wittcoff, H.; Reuben, B. G.; Plotkin, J. S. Industrial Organic Chemicals, 2nd ed.; Wiley: Hoboken, NJ, 2004. 43. Eppelmann, K.; Nossin, P. M. M.; Raeven, L. J. R. M.; et al. WO 2006/005603 and WO 2006/005604, 2005 (DSM). 44. (a) Hayes, D. J.; Fitzpatrick, S.; Hayes, M. H. B.; et al. In Biorefineries – Industrial Processes and Products; Kamm, B., Gruber, P. R., Kamm, M., Eds.; Wiley-VCH: Weinheim, Germany, 2006; Vol. 1 (7), pp 139–164. (b) Rackemann, D. W.; Doherty, W. O. S. Biofuels, Bioproducts and Biorefining, March/April 2011, 5 (2), 198–214. 45. (a) Connor, M. R.; Liao, J. C. Appl. Environ. Microbiol. 2008, 74 (18), 5769. (b) Cann, A. F.; Liao, J. C. Appl. Microbiol. Biotechnol. 2008, 81 (1), 89–98. (c) Connor, M. R.; Atsumi, S. J. Biomed. Biotechnol. 2010, DOI: 10.1155/2010/ 541698. 46. (a) Estrine, B. First International Conference on Renewable Resources and Biorefineries, Ghent, 2005. http://www.rrbconference.ugent.be/presentations/ Estrine%20Boris.pdf (accessed November 23, 2010). (b) Martel, F.; Estrine, B.; Plantier-Royon, R.; et al. Top. Curr. Chem. 2010, 294, 79–115. 47. Nikolaidou, Z.; Schöenicke, P.; Rogut, Y.; et al. 17th European Biomass Conference & Exhibition, Hamburg, 2009. http://www.chimarhellas.com/wp-content/uploads/ 2009/08/biomass-2-july-low.pdf BIOSYNERGYWorkshop_Hamburg_2July2009.pdf (accessed September 23, 2010). 48. Hill, K.; Höfer, R. In Sustainable Solutions for Modern Economies; Höfer, R., Ed.; RSC Publication: Cambridge, UK, 2009, pp 167–237. 49. Frenzel, S.; Peters, S.; Rose, T.; Kunz, M. In Sustainable Solutions for Modern Economies; Höfer, R., Ed.; RSC Publication: Cambridge, UK, 2009, pp 264–299. 50. Chheda, J. N.; Huber, G. W.; Dumesic, J. A. Angew. Chem. Int. Ed. 2007, 46, 7164. 51. Queneau, Y.; Jarosz, S.; Lewandowski, B.; Fitremann, J. Adv. Carbohydr. Chem. Biochem. 2007, 61, 217. 52. (a) Ellis, J. M. H.; Lewis, J. J.; Beattie, R. J., Manufacture of fatty acid esters of sorbitan as surfactants, US Patent 6,362,353, 1999 (ICI). (b) Hill, K.; Le HenFerrenbach, C. In Sugar-Based Surfactants for Consumer Products and Technical Applications; Ruiz, C. C., Ed.; Surfactant Science Series; CRC Press: Boca Raton, FL, 2009; Vol. 143, p 1.
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
53. Riva, S.; Chopineau, J.; Kieboom, A. P. G.; Klibanov, A. M. J. Am. Chem. Soc. 1988, 110, 584. 54. (a) Albertin, L.; Kohlert, C.; Stenzel, M.; et al. Biomacromolecules 2004, 5 (2), 255. (b) Kitagawa, M.; Tokiwa, Y. Carbohydr. Polym. 2006, 64 (2), 218. (c) Rodrigues Borges, M.; Alves dos Santos, J.; Viaira, M.; Balaban, R. Mater. Sci. Eng., C 2009, 29 (2), 519. 55. (a) Griffin, W. C. J. Soc. Cosmet. Chem. 1949, 1, 311. (b) Griffin, W. C. J. Soc. Cosmet. Chem. 1954, 5, 259. (c) Orafidiya, L. O.; Oladimeji, F. A. Int. J. Pharm. 2002, 237 (1–2), 241. 56. (a) Lichtenthaler, F. W. In Biorefineries – Industrial Processes and Products; Kamm, B., Gruber, P. R., Kamm, M., Eds.; Wiley–VCH, Weinheim, Germany, 2006; Vol. 2 (1), pp 3–59. (b) Delmas, M. Chem. Eng. Technol. 2008, 31, 792 57. Picataggio, S.; Beardslee, T. WO 2011/03034, 2011 (Verdezyne). 58. (a) Boussie, T.; Dias, E.; Fresco, Z.; et al. WO 2010/144862, 2010 (Rennovia). (b) Sims, B. Biorefining Mag. Dec 2010, 20. http://issuu.com/BBIInternational/docs/ dec10brm_digital. 59. Schlubach, H. H.; Lührs, E. Justus Liebigs Ann. Chem. 1941, 547 (1), 73. 60. Nishimura, T.; Nakatsubo, F. Cellulose 1997, 4, 109. 61. Karakawa, M.; Kamitakahara, H.; Takano, T.; Nakatsubo, F. Biomacromolecules 2002, 3, 538. 62. Gorius, O.; Bertho, J.-N.; Nizillard, J.-M. Anal. Chim. Acta 2001, 440 (2), 231. 63. Hill, K.; von Rybinski, W.; Stoll, G. Alkyl Polyglycosides – Technology, Properties and Applications; VCH: Weinheim, Germany, 1997. (a) Dewitt, R., Polymères bio sourcés – Normalisation et activités du Groupe SOLVAY, AG ValBiom (2010); http:// www.valbiom.be/files/gallery/presentationsolvayag2010ateliermpr1277457874.pdf (retrieved 15.09.2011). 64. Pang, K.; Kotek, R.; Tonelli, A. Prog. Polym. Sci. 2006, 31, 1009. 65. Amass, W.; Amass, A.; Tighe, B. Polym. Int. 1998, 47, 89. 66. Henton, D. E.; Gruber, P.; Lunt, J.; et al. In Natural Fibers, Biopolymers and Biocomposites; Mohanty, A. K., Misra, M., Drzal, L. T., Eds.; Taylor & Francis Books, Inc., 2005. 67. Jacobsen, S.; Fritz, H. G.; Degée, Ph.; et al. Polymer 2000, 41, 3395. 68. Anderson, K. S.; Schreck, K. M.; Hillmyer, M. A. Polym. Rev. 2008, 48, 85. 69. Gauthier, E.; Fuertes, P.; Cassagnau, P.; et al. J. Polym. Sci. A Polym. Chem. 2009, 47, 1440. 70. Shalaby, S. WO 2004/069918, 2004 (Polymed). 71. Bikiaris, D. N.; Achlias, D. S. Polymer 2008, 49, 3677. 72. (a) Tserki, V.; Matzinos, P.; Pavlidou, E.; et al. Polymer Degradation and Stability 2006, 91 (2), 367–376. (b) Carpenter, K. A.; Shalaby, W. S.; Anneaux, B. L. In Absorbable and Biodegradable Polymers; Shalaby, W. S., Burg, K. J. L., Eds.; CRC Press: Boca Raton, FL, 2004. 73. Fenouillot, F.; Rousseau, A.; Colomines, G.; et al. Prog. Polym. Sci. 2010, 35, 578. 74. Noordover, B. A. J.; van Staalduinen, V. G.; Duchateau, R.; et al. Biomacromolecules 2006, 7, 3406. 75. Doi, Y.; Kitamura, S.; Abe, H. Macromolecules 1995, 28, 4822. 76. Williams, S. F.; Martin, D. P.; Horowitz, D. M.; Peoples, O. P. Int. J. Biol. Macromol. 1999, 25 (1–3), 111. 77. Charbonneau, L.; Johnson, R. E.; Witeler, H. B.; Kanarian, G. U.S. Patent 6,063,464, 2000 (DuPont de Nemours). 78. Gandini, A.; Coelho, D.; Gomes, M.; et al. J. Mater. Chem. 2009, 19, 8656. 79. Gandini, A.; Belgacem, M. N. Prog. Polym. Sci. 1997, 22, 1203. 80. Gandini, A.; Silvestre, A. J. D.; Neto, C. P.; et al. J. Polym. Sci. A Polym. Chem. 2009, 47, 295. 81. (a) Kajiyama, T.; Taguchi, T.; Kobayashi, H.; et al. Polym. Degrad. Stab. 2003, 81 (3), 525. (b) Coulembier, O.; Degée, P.; Hedrick, J. L.; Dubois, P. Prog. Polym. Sci. 2006, 31 (8), 723.
81
82. Pascault, J.-P.; Sautereau, H.; Verdu, J.; Williams, R. J. J. Thermosetting
Polymers; Taylor & Francis Books, Inc., 2002.
83. Boufi, S.; Belgacem, M. N.; Quillerou, J.; Gandini, A. Macromolecules 1993,
26, 6706.
84. Spaans, C. J.; de Groot, J. H.; Dekens, F. G.; Pennings, A. J. U.S. Patent
6,784,273, 1999 (Polyganics).
85. Chang, W. L. U.S. Patent 6,420,446, 2002 (Witco). 86. Frost, J. W. U.S. Patent 2,009,005,532, 2009 (Michigan State University). 87. Schwamborn, M. Polym. Degrad. Stab. 1998, 59, 39. 88. Rohwerder, T. World Congress on Industrial Biotechnology & Bioprocessing,
Washington, DC, 2010, June 27–30.
89. Nishida, H.; Andou, Y.; Watanabe, K.; et al. Macromolecules 2011, 44, 12. 90. Fukuhara, D.; Sundberg, D. J. Coat. Technol. Res. 2005, 2, 509. 91. Fukuoka, S.; Tojo, M.; Hachiya, H.; et al. Polym. J. 2007, 39, 91. 92. Masubuchi, T.; Ueno, E.; Yoshioka, Y.; Tsukimori, Y. WO 088152, 2006 (Asahi Chem. Corp.). 93. Matsuo, J.; Aoki, K.; Sanda, F.; Endo, T. Macromolecules 1998, 31, 4432. 94. Luinstra, G. A. Polym. Rev. 2008, 48 (1), 192. 95. (a) Kuran, W.; Sobczak, M.; Listos, T.; et al. Polymer 2000, 41, 8531. (b) Bisht, K. S.; Svirkin, Y. Y.; Henderson, L. H.; et al. Macromolecules 1997, 30, 7735. 96. (a) Akimichi, O.; Takanori, M. JP Patent 084532 (A), 2009 (Teijin LTD). (b) Noordoven, B.; Duchateau, R.; Koning, C.; et al. WO 2009/033934 A1, 2009 (Dutch Polymer Institute, DPI). 97. Fuji, M.; Akita, M.; Tanaka, T., EP 2 033 981 A1, 2009 (Mitsubishi Chem.).
http://www.japanchemicalweb.jp/ (accessed July 20, 2009).
98. (a) Jansen, B. J. P.; Kamps, J.H.; Looij, H.; Kung, E. WO 2009/052463 A1, 2009 (Sabic). (b) Kinoshita, M.; Saito, M.; Hironaka, K. EP 2149 589 A1, 2010 (Teijin LTD). 99. Gidron, O.; Dadvand, A.; Sheynin, Y.; et al. Chem. Commun. 2011, 47, 1976. 100. Szkudlarek, M. H.; Jansen, J. F. G. A.; Duyvestijn, S. J. WO 2010/108968 A1, 2010 (DSM). 101. Anders, R. M.; Anders, K. R.; Becker, D. K. WO 99/23122, 1998 (Composite Technology Group LLC). (b) Szkudlarek, M. H.; Jansen, J. F. G. A. WO 2010/ 108939 A1, 2010 (DSM). (c) Szkudlarek, M. H.; Jansen, J. F. G. A.; Bleeker, L. J. WO 2010/108941 A1, 2010 (DSM). 102. Gandini, A. In Epoxy Polymers: New Materials and Innovations; Pascault, J.-P., Williams, R. J. J., Eds.; Wiley, 2010; Vol. 55. 103. (a) Takada, Y.; Shinbo, K.; Someya, Y.; et al. J. Appl. Polym. Sci. 2009, 113, 479. (b) Shibata, M.; Nakai, K. J. Polym. Sci. B Polym. Phys. 2010, 48, 425. (c) Stewart, D. Industrial Crops and Products, 2008, 27, 202. (d) El Mansouri, N-E., Yuan, Q., Huang, F., BioResources, 2011, 6, 2492. 104. (a) Feng, X.; East, A. J.; Hammonda, W. B.; et al. Polym. Adv. Technol. 2011, 22, 139. (b) Chrysanthos, M., Galy, J., Pascault, J. P., Polymer, 2011, 52, 3611. 105. Kim, Y. H.; An, E. S.; Park, S. Y.; et al. J. Molecular Catalysis B: Enzymatic 2007, 45, 39. 106. Fitzpatrick, S. W. U.S. Patent 5,608,105, 1995 (Biofine). 107. Nouailhas, H.; Aouf, C.; Le Guerneve, C.; et al. J. Polym. Sci. Part A: Polymer Chemistry, 2011, 49, 2261. 108. (a) Pfeffer, J.; Ortelt, M.; Spyrou, E.; et al. WO 2011/000585 A1, 2011. (b) Pfeffer, J.; Ortelt, M.; Spyrou, E.; et al. WO 2011/000586 A1, 2011. (c) Spyrou, E.; Pfeffer, J.; Loesch, H.; et al. WO 2011/000587 A1, 2011 (Evonik Degussa GmbH). 109. Lindberg, P.; Park, S.; Melis, A. Metab. Eng. 2010, 12, 70–79. 110. Haas, T.; Kircher, K.; Köhler, T.; et al. In Sustainable Solutions for Modern Economies; Höfer, R., Ed.; RSC Publication: Cambridge, UK, 2009, pp 436–478.
82
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
Biographical Sketches Professor Jean-Pierre Pascault has been emeritus at INSA (National Institute of Applied Science), Lyon, France since October 2006. He was professor in the same Institute from 1983 to October 2005; director of the Laboratory of Macromolecular Materials (associated with CNRS) from 1982 to 1998; director of a CNRS Polymer Network Group (FR CNRS) from 2000 to 2006; president of the French Polymer Group (GFP) and of the Polymer Division of the French Chemical Society (SCF) from 2001 to 2004. He has authored more than 300 scientific publications including several book chapters, two books (Thermosetting Polymers (2002) and Epoxy Polymers. New Materials and Innovations (2010)) and more than 30 patents. The key focuses of his research activities are the following: polymer chemistry; (nanostructured) polymer network formation; polyepoxies; polyurethanes; polyacrylates; UV curing; polymer blends; composites; coatings; including bio-based polymers.
Rainer Höfer graduated in inorganic chemistry with Professor Oskar Glemser at the Georg-August Universität zu Göttingen in 1973 with work on sulfur–nitrogen–fluorine chemistry. He spent 3 years at the Technical University of Oran (ENSEP), Algeria, as Maître de Conférences and Directeur de l’Institut de Chimie before joining Henkel in Düsseldorf. With Henkel KGaA and then as vice president of Research & Technology with Cognis GmbH in Monheim, he has assumed global research and development, application technology, technical sales service, strategic business development, and technology scouting responsibilities in oleochemistry, polymer chemistry, and surfactant chemistry for the polymerization, coatings, graphic arts, adhesives, engineering plastics, agrochemical, synthetic lubricants, mining, and pulp and paper markets. He is a founder of Editorial Ecosiris with consultancy and publishing activities in the domains of green chemistry, renewable resources, sustainable development, and interculturation.
Patrick Fuertes graduated in chemical engineering at the University of Marseille (ENSCL) in 1978. Then, he moved to Canada at the University of Quebec (Trois-Rivières) where he had his first experience in the field of cellulose chemistry. At the end of 1981, he joined Roquette, at the R & D Center in Lestrem, northern France. He started in the laboratory of sugar chemistry and was in charge of the Chemistry Department in 1986 with the aim to develop new products and new processes related to starch and sugar chemistry. In 2006, Patrick Fuertes took the responsibility of the Research Division for the coordination of the research programs involving the chemistry, microbiology, fermentation, and biochemistry depart ments. During this period, he worked out the scientific outline of the BioHub® program supported by OSEO Innovation. He was appointed director of the BioHub program in 2009. The object of the BioHub® programme is to develop with industrial and scientific partners new production outlets for chemicals based on renewable agricultural raw materials such as grain.
10.04.1 10.04.1.1 10.04.1.2 10.04.1.3 10.04.2 10.04.2.1 10.04.2.1.1 10.04.2.1.2 10.04.2.2 10.04.2.2.1 10.04.2.2.2 10.04.2.2.3 10.04.2.3 10.04.2.3.1 10.04.2.3.2 10.04.2.3.3 10.04.2.4 10.04.2.5 10.04.3 10.04.3.1 10.04.3.1.1 10.04.3.1.2 10.04.3.1.3 10.04.3.1.4 10.04.3.1.5 10.04.3.2 10.04.3.2.1 10.04.3.2.2 10.04.3.2.3 10.04.3.2.4 10.04.3.2.5 10.04.3.2.6 10.04.3.3 10.04.3.3.1 10.04.3.3.2 10.04.3.4 10.04.3.4.1 10.04.3.4.2 10.04.3.4.3 10.04.3.4.4 10.04.3.4.5 10.04.3.4.6 10.04.3.4.7 10.04.4 10.04.4.1 10.04.4.2 10.04.4.3 References
Introduction Biomass Building Blocks, Chemicals, and Potential Screening Aim of This Chapter Mono-, Di-, and Oligosaccharide-Based Platforms and Building Blocks Carbohydrate-Based C2 Polymer Building Blocks Ethanol production Bioethanol to ethylene and to other monomers Carbohydrate-Based C3 Polymer Building Blocks Lactic acid 1,3-Propanediol (1,3-PDO) 1,2-Propanediol (1,2-PDO) Carbohydrate-Based C4 Polymer Building Blocks Butanol and isobutanol Olefins The biosuccinic acid platform Carbohydrate-Based C5 Polymer Building Blocks Carbohydrate-Based C6 Polymer Building Blocks Carbohydrate-Based Polymers Polyolefins Polyethylene (PE) Polyvinyl chloride (PVC) Polypropylene (PP) C4-derived polymers Polyisoprene Thermoplastics Polyesters General considerations Polylactide acid and polyglycolic acid Aliphatic polyesters: poly(alkylene succinate)s Poly(hydroxyl alkanoates) Aromatic polyesters: poly(alkylene terephthalate)s Emerging polyesters Polyurethanes (PUs) and Polyureas General considerations Bio-based PUs Emerging Products Bio-based polyamides (PAs) Multisegmented block copolymers/TPEs (Meth)acrylic acid and (meth)acrylate families Polycarbonates Furan resins Unsaturated polyesters, UP thermosetting resins Thermosetting epoxy resins Conclusions Specificity of Bio-Based Polymers Commodity and Engineered Materials Future of Polymers from Renewable Resources
Polymer Science: A Comprehensive Reference, Volume 10
doi:10.1016/B978-0-444-53349-4.00254-5
60
60
61
61
62
62
62
63
64
64
64
65
65
65
66
66
67
68
70
70
70
70
71
71
71
71
71
72
73
73
74
74
74
74
75
75
75
75
75
76
77
77
78
78
78
79
79
79
59
60
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
chemistry, enzymatic conversion, and/or fermentation. These building blocks can be used directly or converted into monomers or precursors in order to prepare polymers through standard polymerization processes. 3. To produce bio-based polymers from microorganisms or genetically modified crops.
10.04.1 Introduction 10.04.1.1
Biomass
Biomass means all organic material of biogenic, nonfossil char acter and also comprises living and growing matter in nature and waste materials resulting from both living matter and organic matter that is already dead; the term includes terrestrial and marine plant materials, their residues and by-products, as well as animal and municipal wastes. Specifically, carbohy drates such as starch, cellulose, and hemicellulose are biomass that is produced by plants during the photosynthesis process using sunlight energy, water, and carbon dioxide. Starch is a main constituent of rice, corn, potato, pea, and so on, whereas wood is made up of cellulose (40–50%), hemi cellulose (20–30%), and lignin (15–25%). Carbohydrates are a rich source of C, H, and O elements, which are basic components of organic compounds. Figure 1 gives the formulae of carbohydrates that can be isolated from bio-based feedstocks and that can be used for the production of bio-based polymers. There are three principal routes to produce bio-based polymers:
The first pathway is outside the scope of this chapter, while the third one is currently relevant only for the production of poly(hydroxyl alkanoates) (PHAs) and xanthan, a microbial polysaccharide made by industrial biosynthesis starting from glucose (see Chapter 10.11). This chapter, therefore, focuses mainly on the second pathway that is gaining importance through the development of biorefineries. As an example, sucrose (also called saccharose, or more com monly sugar, Figure 1(b)) is a disaccharide produced at the industrial scale from sugar beet or sugarcane. It is the most widely available low-molar-mass carbohydrate, but until now, sucrose has been mainly used for nutrition purposes or for the fermenta tion industry (e.g., to produce citric acid, bioethanol, and lactic acid) and only to a smaller extent as chemical feedstock. Sucrose is sensitive to acids, and decreasing pH value enhances its hydro lysis into monosaccharides (a mixture of glucose and fructose). The conversion to monosaccharides could also be performed enzymatically. Hydrolysis of a polysaccharide to monosacchar ides is nearly neutral energetically (–20 kJ mol−1 for the hydrolysis of sucrose to glucose and fructose). For bio-based chemical production from biomass, the key reactions involved are not only hydrolysis but also dehydration,
1. To make use of natural polymers such as cellulose, starch, chitin, and lignin, which may be physically or chemically modified and used alone or in combination with other polymers. 2. To produce bio-based chemical intermediates from oligo-, di-, and monosaccharides (Figures 1(a)–1(d)) by means of (a)
OH O
O HO
OH
OH O
O
HO
OH
OH O
O OH
HO
OH O
O OH O
HO
n OH
(b) OH OH O
O
OH
HO HO
OH
(C1)
O
OH
OH
HO
H OH
OH
O
(C2)
O
HO
OH
OH OH
OH
OH (d2)
(d1) OH HO
H OH
O
O
OH
HO
OH OH
OH
Figure 1 Formulae of (a) polysaccharides, n > 10 composed of long chains of monosaccharide units bound together by glycosidic bonds; oligosac charides have the same formula but with n = 3–10; (b) a disaccharide: sucrose; (c1 and c2) monosaccharides; D-glucose, which can exist in both a straight chain (c1) and a ring form (c2); (d1 and d2) D-xylose, d1 is the acyclic form and d2 is one cyclic hemiacetal isomer.
61
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
Fumaric acid
O HO O O
O OH
HO O
OH
HO
OH
HO NH2 O
O OH
HO
Malic acid
3-Hydroxypropionic acid
Amination
OH
Aspartic acid
O
OH
O Succinic acid
Fermentation Fermentation Krebs pathway
NH2
O
OH
HO
Fermentation Glucose
O
OH
Aspartic acid
O O
OH Dehydration
O
HO
O
Fermentation
O
O
OH OH
Hydrogenation
OH OH O Gluconic acid
OH OH O
OH 3-Hydroxybutyrolactone
Oxidation
O
OH
HO
HO
OH
HO
Fermentation and oxidation
NH2 Glutamic acid
Levulinic acid
Oxidation
Itaconic acid
HO
O
Hydroxymethylfurfural
OH
OH
O
HO
OH
O O
O
Dehydration
Fermentation
HO
OH
OH OH OH
HO
OH OH
OH OH O
Sorbitol
Glucaric acid
Figure 2 Top value-added chemicals from glucose. According to Werpy, T.; Petersen, G., Eds. Top Value Added Chemicals from Biomass: Vol. 1— Results of Screening for Potential Candidate from Sugars and Synthesis Gas, US Department of Energy, Office of Scientific and Technical Information, National Renewable Energy Laboratory No.: DOE/GO-102004-1992. www.osti.gov/bridge, 2004.1b
isomerization, aldol condensation, reforming, hydrogenation, and oxidation. As shown as an example in Figure 2, it is possible to produce a wide variety of potential products from a given carbohydrate reactant like glucose. For example, sorbitol, alkyl glycoside, and gluconic acid have already been widely developed for industrial purposes. A similar diagram can be proposed for pentoses (Figure 3). Pentoses are among the major components of hemicelluloses. Various agricultural residues such as corn fiber, corn stover, wheat straw, rice straw, and sugarcane bagasse contain about 20–40% hemicellulose. The second most important abundant polysaccharide in nature!
10.04.1.2 Building Blocks, Chemicals, and Potential Screening In the decade 2000–10, groups of experts from different coun tries have given documented opinions on the use of microorganisms (bacteria and fungi) to improve manufacturing processes and make new products from renewable bio-based feedstocks.1a–h A team from Pacific Northwest National Laboratory and National Renewable Energy Laboratory1b pro posed in 2004 a list of 12 potential bio-based chemicals by examining the potential markets for the building blocks and their derivatives and the technical complexity of the synthesis pathways. The 12 sugar-based multiple functional molecules are listed in Figure 4: 1,4-diacids (succinic, fumaric, and malic
acids), 2,5-furan dicarboxylic acid (FDCA), 3-hydroxypropionic acid (HPA), aspartic acid, glucaric acid, glutamic acid, itaconic acid, levulinic acid, 3-hydroxybutyrolactone, glycerol, sorbitol, and xylitol/arabinitol.1b Another report released in 2007 proposed additional build ing blocks as viable candidates: gluconic acid, lactic acid, malonic acid, propionic acid, citric and aconitic triacids, xylo nic acid, acetoin, furfural, levuglucosan, lysine, serine, and threonine.1d But as the development of a bio-based industry requires the evaluation of a broad range of conversion technologies, includ ing enzymatic, catalytic, and thermochemical processes, these previous reports do not give a closed list. As an example, evaluation in 2009 of recent technology advances provides a revised list of bio-based product opportunities from carbohy drates slightly different and focusing on: ethanol, furans, glycerol and derivatives, biohydrocarbons such as isoprene, lactic, succinic, hydroxypropionic and levulinic acids, and also sorbitol and xylitol.2 If these lists are important for the establishment of new biorefineries integrating biofuels and chemical productions, they have to be considered just as dynamic guides.
10.04.1.3
Aim of This Chapter
The aim of this chapter is to describe how carbohydrates can be used as supply alternatives for C2, C3, C4, C5, C6 platform
62
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
Xylose O
OH OH
HO OH
Hydrogenation
OH
OH
OH
HO
OH H3C Propylene glycol
OH OH
Xylitol
Oxidation OH HO Ethylene glycol OH
OH
HO
OH O
OH
OH
O
HO
OH
Xylaric acid
Glycerol 1f
Figure 3 Xylitol as a platform chemical. Source: Michigan Biotechnology Institute.
chemicals and how biosourced polymers can be produced from such carbohydrate-based building blocks. The chapter will be divided into two parts. The first part describes the synthesis of main building blocks that are or will be used to prepare poly mers similar to the ones from petrochemical industry or novel polymers. The second part relates how polymers based on renewable resources are made, their properties, and applica tions; it contains several subparts dealing with different families of polymers and a last one focusing on novel polymers that have growth potential.
10.04.2 Mono-, Di-, and Oligosaccharide-Based Platforms and Building Blocks 10.04.2.1 10.04.2.1.1
Carbohydrate-Based C2 Polymer Building Blocks Ethanol production
Industrial ethanol fermentation is one of the best existing off sets to a petrochemical refinery producing transportation fuel and a chemical raw material in one. The manufacturing process for bioethanol has been industrial state of the art since the Brazilian Proálcool initiative3 of the 1970s and is mostly accomplished by anaerobic batch fermentation.4 A variety of sugar crops can be used for producing bioethanol, including sugarcane, sugar beet, and sweet sorghum, all of which contain a large proportion of sucrose. After conditioning, an aqueous raw sugar juice (sucrose syrup) is extracted. Using starch crops such as corn or wheat adds an additional step, the depolymer ization of amylose and amylopectin structures by enzymatic
liquefaction and saccharification to yield glucose syrup (Figure 5). To make lignocellulose an amenable raw material for bioethanol, it needs to undergo treatments that release its monomeric sugars, which then can be converted by fermentation. The two main steps are as follows: (1) a pretreatment (by physical or chemical procedures) that releases hexoses and pentoses from hemicellulose; and (2) an enzymatic treatment (or, alternatively, hydrolysis by chemical procedures) that gen erates glucose from cellulose. Unlike sugarcane processing, in which hexoses such as glucose and fructose are the only monomers released, lignocellulose substrates release both pentoses and hexoses. Pentoses, however, are not easily fermented by Saccharomyces cerevisiae, the preferred microorganism in crop-based glucose fermentation. Although two groups of microorganisms, that is, enteric bacteria and some yeasts, are able to ferment pentoses, efficient ‘white biotechnology’ processes for ethanol produc tion based on hemicelluloses and lignin in a so-called Lignocellulosic Feedstock (LCF) biorefinery are still a subject of intensive research and have not yet been established industrially.6 As alternatives to batch fermentation, continuous processes have been developed in order to reduce production costs and to improve process efficiency and ethanol yield.7 Although there are several routes for the manufacture of synthetic ethanol starting from fossil ethylene, such as the indirect catalytic hydration or the direct gas phase hydration,
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
63
(a) 1,4-Diacids HO
HO
O
O
HO
O
HO O
OH
O
Succinic acid
O
OH
Fumaric acid
OH
Malic acid
(b) 2,5-Furan dicarboxylic acid (FDCA) O
O
O
HO
OH
FDCA
(c) 3-Hydroxy propionic acid (3-HPA); glucaric acid; glutamic acid O
O HO
OH
OH
O
OH OH
HO
HO
OH NH2
OH OH O Glucaric acid
3-HPA
O
Glutamic acid
(d) Itaconic acid; levulinic acid; 3-hydroxybutyrolactone O
O
O OH
HO
O
HO
O
O
Itaconic acid
OH 3-Hydroxybutyrolactone
Levulinic acid
(e) Glycerol, sorbitol, and xylitol/arabinitol OH
OH HO
OH Glycerol
OH
OH OH
HO OH OH Sorbitol
OH
HO
OH OH Xylitol
Figure 4 Formulae of the 12 sugar-based multiple functional molecules: (a) 1,4-diacids; (b) FDCA; (c) 3-HPA, glucaric acid, glutamic acid, (d) itaconic acid, levulinic acid, 3-hydroxybutyrolactone; (e) glycerol, sorbitol, and xylitol/arabinitol.1b
on a global scale, synthetic feedstocks play a minor role for industrial ethanol production. At the end of the 1990s, only 7% of overall output accounted for synthetic feedstocks. Roughly 60% of world ethanol production has been from sugar crops, both cane and beet, with most of the remainder coming from grain, with maize playing a dominant role.8
10.04.2.1.2
Bioethanol to ethylene and to other monomers
The steam cracking process, which employs petroleum frac tions and natural gas liquids as feedstocks, is the dominant method for large-scale ethylene production worldwide. However, the improved economics of sucrose fermentation makes bioethanol a highly interesting alternative feedstock and puts the ‘bioethanol-to-ethylene’ (BETE) technology in the center of a biomass value chain covering fermentable
carbohydrate raw materials, polymerizable intermediates, and key polymer commodities. Fuel-grade ‘dry’ bioethanol is rather easily dehydrated to ethylene in an isothermal tubular reactor using aluminum oxide/magnesium oxide catalyst. The practical ethylene purity is approximately 94%. The presence of water in the ethanol feed is detrimental to the dehydration reaction. The mechanism for the ethanol dehydration assumes a simulta neous reaction: diethyl ether is considered an intermediate and not a by-product (Figure 6). Its formation is favored mainly between 150 and 300 °C, while ethylene formation is predominant between 320 and 450 °C.3,9 Alternatively, zeolite catalysts allow the production of prac tically pure ethylene from aqueous ethanol. This also means that ethylene can be produced directly from ethanol fermenta tion broth in a one-step process; for example, a superacidic
64
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
Starting material
Production of sugar containing substrate
Production of ethanol C6H12O6
Sugar-containing biomass
Washing, crushing
Extraction of sugar juice
Starch-containing biomass
Washing, crushing
Dry milling wet milling
2 C2H5OH + 2 CO2
Fermentation
Saccharification
Separation Yeast
Lignocellulosecontaining biomass
Pretreatment delignification
Acid/enzymatic hydrolysis
Saccharification
Distillation/ rectification Mash Dehydration
By-products
Bioethanol Figure 5 Production processes for bioethanol.5
2 CH3CH2OH
CH3CH2OCH2CH3 + H2O
H2C = CH2 + 2 H2O
Figure 6 Mechanism for the ethanol dehydration.
ZSM-5 zeolite can catalyze the dehydration reaction at tem peratures as low as 170 °C and under atmospheric pressure.10 Nonetheless, stability of the catalyst is not fully satisfactory and developing ZSM-5 zeolite and more particularly microscale and nanoscale HZSM-5 zeolite catalysts with high efficiency under lower reaction temperature to substitute alumina cat alyst is a field of active research. Besides pure or doped alumina and zeolites, many other catalysts have been studied for ethylene production via ethanol dehydration.11 The reac tors are usually tube-array, fixed-bed reactors with low ethylene yield, and relatively high reaction temperature (350–450 °C), while fluidized bed and microreactor technol ogies are under investigation.12 Technical concepts and designs for biorefineries taking advan tage of the benefits of a fully integrated chemical processing unit that would go from sugarcane to upstream ethylene derivatives such as vinyl chloride monomer (VCM), ethylene oxide (EO), and polyethylene (PE) have been developed by various engineer ing companies. With already established infrastructures, integrative plant concepts such as the ‘Biorefinery Leuna’ vision might be a promising and pragmatic approach.6c,13
10.04.2.2
Carbohydrate-Based C3 Polymer Building Blocks
C3 bio-based building blocks are mainly produced from gly cerol, which is produced in huge amounts as a by-product of splitting fats and oil (see Chapter 10.03). However, the produc tion of lactic acid and 1,3-propanediol (PDO) by fermentation is one of the best examples of successful industrial develop ment of carbohydrate-sourced, bio-based monomers for making new polymers.
10.04.2.2.1
Lactic acid
Two different types of lactic acid (CH3-CH(OH)-C(O)OH; also known as 2-hydroxypropionic acid or milk acid) can be pro duced by fermentation: both L(+)- and D(–)-lactic acid can be obtained by using an appropriate bacterial or fungal strain. Lactic acid bacteria are classified into homofermentative and heterofermentative. Homofermentative lactic acid bacteria pro duce virtually a pure lactic acid, whereas heterofermentative lactic acid bacteria produce other products such as ethanol, formate, or acetic acid along with lactic acid. The main homofermentative lactic acid bacteria used for the production of lactic acid from different carbon sources are Lactococcus lactis, Lactobacillus delbrueckii, Lactobacillus helveticus, and Lactobacillus casei. Amylolytic bacteria such as Lactobacillus amylovorus can convert liquefied starch to lactic acid with a high productivity.14 The current strains for industrial production of L(+)-lactic acid allow very good yield and productivity to be achieved: product concentration in industrial fermentations goes up to 180 g l−1 with lactic acid yield of 90% of fermentable sugars and a production rate of 5 g l−1 h−1. A wide variety of carbohydrate sources such as molasses, corn syrup, whey, glucose, and sucrose can be used for lactic acid production. Thermophilic homofermentative lactobacteria have been widely used for lactic acid production but require a careful pH control between 5.5 and 6.5 using neutralizing agent during the fermentation. Consequently, the recovery of lactic acid usually generates a large amount of by-products such as calcium sulfate. In order to get rid of this main issue, commercial lactic acid fermentation has now been developed, which is carried out under acidic conditions.15
10.04.2.2.2
1,3-Propanediol (1,3-PDO)
1,3-PDO can be produced by fermentation from glycerol, with different strains such as Klebsiella pneumoniae, Clostridium butyr icum, Clostridium pasteurianum, and Citrobacter freundii.
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
Drawbacks of industrial fermentation using these strains are strong inhibition of 1,3-PDO production and by-products dur ing fermentation. There are no naturally occurring microorganisms known to produce 1,3-PDO from glucose. DuPont in collaboration with Genencor and Tate & Lyle has developed a recombinant pro duction organism as well as a fermentation process to produce 1,3-PDO from glucose.16 The strain is based on an Escherichia coli K12 substantially engineered in order to obtain outstanding performances compared to glycerol fermentation. However, the increasing availability of glycerol due to increas ing biodiesel production and subsequently falling prices of this raw material could make glycerol fermentations more attractive. Recently, a recombinant C. butyricum producing 1,3-PDO with low amount of butyrate, butanol, acetone, and lactate has been patented by Metabolic Explorer.17 In addition, the downstream process has also been optimized in order to produce a purified grade of 1,3-PDO.18a 1.3-PDO can be formulated into a variety of polymers, inter alia polyesters, polytrimethylene terephthalate (PTT), composites, adhesives and coatings.18b,c
10.04.2.2.3
1,2-Propanediol (1,2-PDO)
1,2-PDO or propylene glycol (PG), a C3 dialcohol, is a widely used chemical. It is currently produced by chemical means using a propylene oxide hydration process. It is a component of not only unsaturated polyester (UP) resins or polyur ethanes (PUs) but also coolants, antifreeze, and deicing fluids for aircraft and has been increasingly used as a replace ment for ethylene glycol, which is recognized as being more toxic. Alternatively, bio-based PG can be produced by thermoche mical conversion of glycerol or purified alditols such as sorbitol. The thermochemical routes consist of a hydrogenolysis reaction in which the starting compound is catalytically converted, under heating and reducing conditions, into a mixture of glycols. Depending on the catalyst used for the hydrogenolysis, high selectivities to 1,2- or 1,3-PDO can be obtained.19 Global Biochem is currently producing industrial quantities of 1,2-PDO from sorbitol. A fermentation process for
65
producing 1,2-PDO from sucrose using a metabolically engi neered E. coli strain has also been reported.20
10.04.2.3 10.04.2.3.1
Carbohydrate-Based C4 Polymer Building Blocks Butanol and isobutanol
Actually, C4 building blocks of industrial relevance, more par ticularly butadiene, butene, butane, butanol, and maleic anhydride, rely on fossil raw materials produced in the steam cracker as a by-product in the cracking of naphtha (light gaso line) to ethene and propene. Hydroformylation of propene yields n- and isobutanol (2-methyl-1-propanol) depending on reaction conditions. Butanol/diesel and butanol/gasoline blends can be used in unmodified or slightly modified engines as transportation fuel.4 Butanol does not absorb moisture from air. Its energy content of 29.2 MJ l−1 is higher than ethanol (19.6 MJ l−1) and compares well with gasoline (32 MJ l−1). The potential use as a biofuel has created considerable interest in biobutanol as com pared to fossil fuel and bioethanol, and this is even more so as biobutanol would also be an important building block for C4-derived polymers (Figure 7). Furthermore, the manufactur ing of n-butanol by fermentation was the industry standard until the 1950s. Starting from corn production is actually prac ticed again by Cathay Industrial Biotech in Shandong /China. Alternatively, Cobalt Technologies in a strategic alliance with Rhodia (a member of the Solvay group) is exploring sugar cane bagasse as a feedstock on site in Brazil.22 The acetone–butanol or acetone–butanol–ethanol (ABE) fermentation using the Weizman organism Clostridium acetobutylicum or Clostridium beijerinckii under anaerobic conditions produces the three sol vents in a ratio of ABE = 3:6:1.23 More recently, microbial fermentation technologies, which genetically alter E. coli to generate several higher chain alcohols from glucose, including 1-butanol, 2-methyl-1-butanol, and more particularly isobutanol, have been developed. The tech nologies metabolically engineer E. coli’s amino acid biosynthetic pathway to divert its 2-keto acid intermediates to aldehydes by 2-keto acid decarboxylases (KDCs) and then to (b) Glucose Transhydrogenase
(a)
2 NADH
Gasoline replacement
Biocatalyst Enzymes nutrients
Fuels
Liquids Chemicals
Solids Fermentation
Jet fuel replacement
2CO2
Acetolactate KARI
Distillation Milling
2 Pyruvate ALS
Diesel replacement
2 NADPH
NADPH
2,3-Dihydroxvy-isovalerate DHAD α-Keto-isovalerate
Plastics Biomass
Drying
Feed
products
KIVD
H2O
Isobutyraldehyde
Fibers
NADPH
ADH Isobutanol
Figure 7 (a) The biobutanol value chain (with the kind permission of Lanxess). (b) Metabolic pathway for the conversion of glucose to isobutanol.21
66
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
alcohols by alcohol dehydrogenases (ADHs).21,24 Alternatively, an isobutanol production platform based on the amino acid-producing Corynebacterium glutamicum showed an increased tolerance to isobutanol relative to E. coli.25
10.04.2.3.2
Olefins
In an acid-catalyzed elimination reaction involving the loss of H2O (dehydration), isobutanol can be converted into a mix ture of C4 olefins (1-butene, cis-2-butene, trans-2-butene, and isobutene),26 which then convert into a mixture of unreacted isobutene and 1,3-butadiene in a catalytic dehydrogenation reaction at elevated temperature and low pressure well known from petrochemical process technologies.24,27 Lanxess and Gevo have developed a process for the produc tion of isobutene from isobutanol derived from grain crops, sugarcane, as well as cellulose. Meanwhile, Global Bioenergies has engineered an initial series of bacterial strains that can produce isobutene by transforming glucose in vivo.28
10.04.2.3.3
The biosuccinic acid platform
• Maleic anhydride has traditionally been manufactured by the oxidation of benzene but is now predominantly produced by using n-butane as a feedstock (Figure 8):27b Maleic acid is manufactured by hydrolysis of maleic anhydride. There are, however, few applications for maleic acid, the major industrial use being the isomerization into fumaric acid.29 Fumaric acid occurs naturally in many plants and is named after Fumaria officinalis, a climbing annual plant, from which it was first isolated. Currently, industrial synthesis of fumaric acid is mostly based on catalytic isomer ization of maleic acid in aqueous solutions. However, it could also be produced from glucose by fungal fermentation by Rhizopus oryzae.30 Fumaric acid is an industrial bulk che mical with an annual consumption of nearly 130 000 mto in 2006. Fumaric acid is used as acidulant in the food and beverage industries; to react with rosin from crude tall oil (CTO) distillation for the manufacture of fortified rosin paper sizes; and in place of maleic anhydride in alkyd and UP resins. Malic acid (hydroxybutanedioic acid, HOOCCH (OH)CH2COOH) is produced by the hydration of either fumaric or maleic acid. It is also a natural acid found in green apples and other unripe fruits. It is a crystalline solid that is used as an acidulant as well as a flavoring agent in the processing of beverages, confections, food, and personal care products. • In contrast to the BETE value chain, carbohydrate-based C4 building blocks do not only substitute crude oil-derived crack C4 intermediates but also complement the platform
O
2 CH3CH2CH2CH3 + 7 O2
2
O + 8 H2O
O Figure 8 Synthesis of maleic anhydride from n-butane.
and provide new opportunities for C4-based polymers. This is in particular the case for succinic acid (butanedioic acid) that has been produced for the use as a natural antibiotic and general curative since it was derived by dry distillation from amber (which gave the name amber acid still used in the German language: Bernsteinsäure) for the first time (Gregorius Agricola, 1546). Although the bulk of the actual industrial production of succinic acid is made by hydroge nation of maleic anhydride and subsequent hydration, ‘white biotechnology’ is gaining considerable interest as an environmentally sound alternative. Succinic acid is a component of the Krebs cycle (also called tricarboxylic acid (TCA) cycle and citric acid cycle), the process by which aerobic organisms convert carbohydrates, fats, and proteins into carbon dioxide and water to generate a form of usable energy they need to grow and divide. This meta bolic process and thus the biosynthesis of succinic acid occurs in most plants, animals, fungi, and many bacteria. Furthermore, fermentation of glucose to yield succinic acid has distinct advantages. While during bioethanol produc tion, for example, 2 mol of inert waste CO2 per mole of glucose are formed, biosuccinic acid production is a CO2-fixing operation:31 Bioethanol fermentation : C6 H12 O6 → 2C2 H5 OH þ 2CO2 Biosuccinic acid fermentation : C6 H12 O6 þ 2CO2 → 2C4 H6 O4 Inter alia, Lee and coworkers32 have studied Actinobacillus succinogenes, Mannheimia succiniciproducens, and Anaerobiospirillum succiniciproducens isolated from bovine rumen as natural succinic acid overproducers for bacterial fermentation of glucose. More recently, Song and Lee,33a Bechthold et al.,33b and Cukalovic and Stevens33c have put together the many different microorganisms that have been screened and studied for biotechnological succinic acid pro duction. Stability of the microorganisms, handling, and the downstream purification, that is, the separation of by-products such as acetic acid, formic acid, lactic acid, and pyruvic acid, are still a major issue for industrial production. On the other hand, it has long been known that E. coli fermentation produces a mixture of formic, lactic, and succi nic acids – however, at low yield and with succinic acid as a minor component only.34 Indeed, the biochemical pathway of succinic acid production in E. coli proceeds in several conversion steps from pyruvic acid to oxaloacetic acid, which is then converted to malic acid, fumaric acid, and succinic acid. Bioengineering research at Argonne National Lab. and others using robust E. coli mutants succeeded in improving the yield of succinic acid as the final product.35 They could also show that this pathway allows for a con trolled synthesis of the intermediate malic and fumaric acids. If fumaric acid is the product of choice, the gene that codes for the enzyme responsible for the conversion of fumaric acid to succinic acid is deleted and the resulting organism will amass fumaric acid instead of succinic acid. If malic acid is the desired product, the gene that codes for the enzyme
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
responsible for the conversion of malic to fumaric acid is deleted to make a malic acid-producing organism. Production methods for fumaric acid including production by different fermentation processes have recently been reviewed by Roa Engel et al.36 • ‘White biotechnology’ for the industrial synthesis of succinic acid was first practiced in Pomacle/F by BioAmber, a joint venture of Agro-Industrie Recherche (ARD) and DNP Green Technology. The same year, 2010 Reverdia (DSM/Roquette), Mitsubishi/PTT, BASF/Purac, and Myriant/Uhde developed industrial-scale biosuccinic acid operations. Raw material for biosuccinic acid synthesis would be any sugar-containing feedstock including glucose syrup from hydrolyzed starch, grain sorghum, corn steep liquor from wet milling, lactose from whey, and lignocellulosic hydrolysate produced by acid or enzyme hydrolysis. As already mentioned, the separation of pure succinic acid from the fermentation broth is another critical issue. Several methods have been developed, such as acidulation, solvent extraction and crystallization, electrodialysis, preci pitation as Ca2+ or Mg2+ salt,37 the use of tri-n-octylamine as a reactive phase transfer extractant,38 or reactive distillation with ethanol.39 The latter method would allow the direct production of diethyl succinate as intermediate for further conversion, for example, by transesterification. The develop ment of metabolically engineered yeast strains enables the fermentation to be run at low pH and consequently avoids the production of large amounts of salt during the down stream process.40 Hydrogenation of succinic acid or its dialkyl esters leads to 1,4-butanediol (BDO)41 – as an alternative to other man ufacturing processes such as the Reppe process starting from
67
acetylene, Mitsubishi’s butadiene–acetic acid process, Kuraray’s propylene oxide/allyl alcohol technology, or Toyo Soda’s dichlorobutene process.27b The acid-catalyzed dehy dration of 1,4-BDO yields tetrahydrofuran (THF) (Figure 9). • 1,4-Diaminobutane is manufactured by adding hydrocya nic acid to acrylonitrile in the presence of an alkaline catalyst such as triethylamine and then hydrogenating the succinic dinitrile intermediate.42 Therefore, the direct bio synthesis that can be achieved using a microorganism with increased ornithine decarboxylase (ODC) activity and N-acetylglutamate formation activity is a highly attractive alternative.43 Preferably, the ODC-encoding gene is inter alia originating from E. coli.
10.04.2.4
Carbohydrate-Based C5 Polymer Building Blocks
Carbohydrate-based C5 platform chemicals are formed by depolymerization of hemicelluloses or by C1 abstraction from C6 carbohydrates such as the synthesis of levulinic acid from hydroxymethylfurfural (HMF). ‘Levulinic acid’ (4-oxo pentanoic acid) is an interesting intermediate for the synthesis of low-molar-mass chemicals. The oxidation of levu linic acid offers an alternative route for the synthesis of succinic acid.44 It is also well known that during glucose fermentation to produce wine, beer, or schnapps, small amounts of fusel alcohols (also called fusel oil), more particularly 1-propanol, 2-propanol, various isomers of butanol, and amyl alcohol, are formed as by-products. The same applies for the production of biobutanol and the genes involved in the production of inter mediates that are converted into fusel alcohol components are known. Controlled overexpression of these genes can be tuned to produce specifically amyl alcohol isomers such as 3-methyl 1-butanol (isopentyl alcohol and isobutyl carbinol) or OH
HO
1,4-Butanediol OH HO HO
O
Esterification
O MeOOC
COOMe
OH OH
Tetrahydrofuran
Fermentation
HOOC
O
-Butyrolactone
Hydrogenation COOH
O
Dehydration
Succinic acid HOOC
COOH
O
Fumaric acid
O Dehydrogenation cyclization
O
COOH COOH
Maleic acid
Figure 9 Succinic acid as a platform chemical. Adapted from Bozell, J. J.; Petersen, G. R. Green Chem. 2010, 12, 539.2 Reproduced by permission of The Royal Society of Chemistry.
68
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
2-methyl-1-butanol.21,45 Similar to the synthesis of butene and butadiene by dehydration of butanol, the dehydration of pen tanols such as 3-methyl-1-butanol or 2-methyl-1-butanol yields multiple C5 olefin isomers. Dehydrogenation of these pentene mixtures followed by appropriate separation technol ogies produces pure ‘isoprene’.21,44 Depolymerization of hemicelluloses (pentosans) by acid-catalyzed hydrolysis yields pentoses, principally xylose, which is then dehydrated to ‘furfural’. Pentosans are present in sugarcane bagasse, corncobs, cottonseed, and rice hulls, that is, in biomass waste of vegetable oil or sucrose production. Alternatively, chemical or enzymatic hydrolysis of wood would convert cellulose to glucose (e.g., for bioethanol or bio succinic acid production) and hemicelluloses to pentoses, which are then converted to furfural. Furfural as a C5 platform inter mediate is hydrogenated in the presence of a Cu2Cr2O5 catalyst yielding ‘furfuryl alcohol’, the starting monomer for furan resins (Figure 10). Decarbonylation of furfural yields furan which can be converted by catalytic hydrogenation into tetrahydrofuran (THF). However, this route is not widely practiced. The thermo/chemical or enzymatic hydrolysis of hemicellu loses from wheat straw or bran yielding a pentose syrup that can be converted into alkyl polypentosides (APPs) is a
promising route to new fully renewable surfactants as alterna tives to alkyl polyglucosides (APGs).46 On an industrial scale, APPs are manufactured in analogy to one of the two methods conventionally used for preparing APGs. The first method con sists of reacting the pentose syrup and the fatty alcohol directly in the presence of an acid catalyst in order to obtain the poly pentosides (Figure 11). The second method consists of carrying out glycosidation, in a first step, with a short-chain C1–C5 alcohol and, in a second step, making a transglycosidation, which consists of displacing the short-chain alcohol with a C12–18 fatty alcohol.48
10.04.2.5
Carbohydrate-Based C6 Polymer Building Blocks
• The six-carbon monosaccharide glucose is quasiomnipresent in nature. Glucose is one of the main products of photosynthesis and starts cellular respiration. Glucose serves as an energy carrier (blood glucose) and as a molecular component in energy storage or structural polysaccharides (e.g., starch or cellulose). Lactose, the predominant sugar in milk, is a glucose–galactose disaccharide; sucrose (also called
H2 –H2O; R = H
H2, –CO
CHO
O Furfural
Furfuryl alcohol CH2OH
O
THF O
R
O
O OH
HO HO
COOH + HCOOH Levulinic acid
OH
–H2O R = CH2OH [O]
HO O
CHO
HMF –H2O
OHC [O]
HO
OH
V, Co catalysts –H2O
HOOC
O
OH Fructose
O
COOH
FDCA 2
Figure 10 Synthesis and transformation of furans. Reproduced by permission of The Royal Society of Chemistry.
O HO
ROH, H+ OH
H
O O
O DP
H2O Figure 11 Synthesis of APP.47 Reproduced by permission of Elsevier.
CHO
Diformylfuran
OH
HO
O
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
saccharose) is a disaccharide of anomerically linked D-glucose and D-fructose. • As a C6 polymer building block, glucose is a particularly flexible feedstock that can be valorized by (1) degradation of the C6 framework yielding C2 (e.g., bioethanol), C3 (e.g., glycerol and 3-HPA), C4 (e.g., butanol, succinic, fuma ric, malic, and aspartic acids) or C5 (e.g., amyl alcohol and glutamic acid) platform chemicals, (2) derivatization by maintaining the C6 framework, and (3) conversion into >C6 organic compounds, leading to a wide variety of pro mising organic building blocks or intermediates.49–51 The β-D-fructofuranosyl α-D-glucopyranoside structure of sucrose is maintained in sucrose or sugar esters. Sucrose esters are nonionic, surface-active materials with very mild dermatological properties. They are manufactured by transesterification of sucrose with fatty acid methyl esters (FAME) in a polar solvent or an emulsion process or in a melt process where sucrose and FAME react without any solvent under heterogeneous alkaline catalysis (K2CO3). Selectivity is diffi cult to achieve and typically a mixture of mono-, di-, tri-, tetra-, and pentaesters are formed.49,52 However, selective formation of sugar monoesters can be achieved by enzyma tically catalyzed transesterification.53 Similarly, vinyl esters (VEs) and sugars can react in suitable organic and microaqu eous media under enzymatic catalysis yielding glycomonomers such as 6-O-vinyladipoyl-D-glucose (Figure 12). Such vinyl sugar esters can be polymerized by a radical polymerization reaction yielding glycopolymers, a class of
H2C
biodegradable polymers that contain carbohydrate moieties as pendant or terminal groups.54 • Glucose can be readily hydrogenated in a batch or continuous-slurry process yielding ‘sorbitol’. The catalysts are generally various types of supported nickel or Raney nickel. However, large-scale production of sorbitol uses corn starch (glucose syrup) as raw material. Besides the use as a feedstock in vitamin C synthesis and as humectants in foods, cosmetics, and medicinal products, sorbitol and other sugar alcohols such as mannitol and xylitol may be employed as building blocks for polymer synthesis. Dehydration of sorbitol in the presence of an acid catalyst forms ‘1,4-sorbitan’ which can react with fatty acids yielding sorbitan fatty acid esters.32 Sorbitan fatty acid esters (Span) and their polyglycol ethers (Tween or polysorbate) are oleo philic W/O and hydrophilic O/W emulsifiers, respectively. Indeed, Span and Tween have been kind of archetypes for the hydrophile–lipophile balance (HLB) concept developed by Griffin as a means to formulate stable aqueous emulsions of cosmetic or industrial oils.52,55 The double dehydration of sorbitol yields isosorbide (1,4:3,6-dianhydro-D-glucitol), while the triple dehydration of glucose and other hexoses generates 5-(hydroxymethyl) furfural (HMF), which can be oxidized to 2,5-furandicar boxylic acid (FDCA), any of which is an example for high-potential, C6-derived building blocks for the synthesis of new biopolymers (Figure 10).56 Potential chemicals that may be derived from FDCA are diols such as 2,5-dihydroxymethyl furan or 2,5-dihydroxymethyl
O O O O
CH2
Divinyl adipate HO
O
H2C O
OH
OH OH D-Glucose
O
O O
O
OH Protease from Bacillus subitillis, DMF/water(95/5) 50 °C, 5 days, 150 rpm
69
OH OH 6-O-Vinyladipoyl D-Glucose
OH OH
K2S2O8/H2O2, 60 °C, 24 h
H2 C
H C n O
O O
O
O OH
OH
OH Poly(6-O-Vinyladipoyl D-Glucose) Figure 12 Chemoenzymatic synthesis outline to produce the poly(6-O-vinyladipoyl-D-glucose).54c
OH
70
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
Hexoses O
HO
O
O O Furans O
H
OH
H
2,5-Furandicarbaldehyde
Succinic acid O
O
O
HO
OH
2,5-FDCA
O
O
NH2
H2N
HO
2,5-Bis(aminomethyl)tetrahydrofuran
OH
2,5-Dihydroxymethyl furan O HO
OH
2,5-Dihydroxymethyl tetrahydrofuran 1f
Figure 13 FDCA as a platform chemical. Source: Michigan Biotechnology Institute.
tetrahydrofuran and also diamines like 2,5-bis(amino methyl)tetrahydrofuran (Figure 13). • Adipic acid is the most important dicarboxylic acid for the production of polyamides (PAs). The majority of the 2.2 Mio mto of adipic acid produced annually (2006) is used as monomer for the production of PA66 by a polycondensation reaction with hexamethylenediamine (Section 10.04.3.4.1). Adipic acid is currently predominantly produced in a two-step process by oxidation of cyclohexane with cyclohexanol/cyclohexanone (Anol-Anon or KA oil) as intermediate.27b Verdezyne has developed a process to produce adipic acid by a yeast microorganism. Using proprietary tech nologies, Verdezyne discovered and is engineering a metabolic pathway that can utilize sugar, plant-based oil, or alkanes.57 In addition, a new route for the production of adipic acid from glucose has been recently announced by Rennovia. The process includes the catalytic oxidation of glucose to glucaric acid followed by a catalytic reductive dehydroxylation to produce adipic acid.58 • The acid-catalyzed hydrolysis of cellulose as well as the mechanism of enzymatic cellulose biodegradation, the mechanisms of mercerization, and the relationship between the chemical structure of cellulose derivatives and their phy sicochemical and mechanical properties are topics of intense research in order to make cellulosic biomass available for glucose-based white biotechnology and structurally stable biopolymers. In such investigations, methods to synthesize cellulose in a kind of reverse hydrolysis would enable the design of model compounds and control the degree of polymerization and/or depolymerization. Pathways for synthesis of cellulose have been investigated by Schlubach and Lührs59 and later by Nishimura and Nakatsubo.60 The polymerization of glucose derivatives to
produce stereoregular polysaccharides has also been achieved by cationic ring-opening polymerization (ROP) of glucose orthopivalate.61 Starting from substituted glucose monomers, the formation of glucose oligomers, however, is easily achieved. Indeed, APGs result from the Fischer reaction of glucose with a fatty alcohol. The monoalkylated glucose further reacts with free glucose under the same conditions to yield APG.62 APGs are nonionic surfactants combining a vegetable oil-derived fatty alcohol and sugar and thus are completely based on renewable resources.52,63 The glucose oligomer imparts the hydrophilic moiety of the surfactant molecule.
10.04.3 Carbohydrate-Based Polymers 10.04.3.1 10.04.3.1.1
Polyolefins Polyethylene (PE)
PE is by far the most important product made of ethylene chain polymerization. Bio-based PE has exactly the same chemical, physical, and mechanical properties as petrochemical PE. Since the beginning of the new millennium, Brazil has become the bonfire for green PE production using the described value chain (Section 10.04.2.1) sugarcane, bioethanol, bioethylene, bio polyethylene (Braskem, Santelisa Vale/Crystalsev, and Dow).
10.04.3.1.2
Polyvinyl chloride (PVC)
PVC is also obtained by chain polymerization of its monomer, produced from chlorine (57 wt.%, manufactured by the chlor alkali electrolysis of brine yielding chlorine, sodium hydroxide, and hydrogen as coproducts) and ethylene (43 wt.%) via 1.2-dichloroethane. PVC and its precursors are by far the most important value-adding chlorine disposal route. For the production of bio-based PVC, bioethylene is derived from bioethanol. Solvay Indupa has announced plans to produce PVC from partly bio-based feedstock on their manufacturing
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides site in Santo Andre/BR.63a As PE, PVC produced from bio-based ethylene can fully substitute PVC from conventional production.
10.04.3.1.3
Polypropylene (PP)
Bioethylene also opens a gateway to C3 building blocks such as propylene (the second most important organic building block for polymers after ethylene) to be manufactured by enzymebased fermentation. However, the first commercial size plant that has been commissioned by Braskem with a capacity of 30.000 mto polypropylene eventually will dimerize sugar canebased bioethylene to make butylene, and then through metath esis, convert ethylene and butylene into biopropylene.
10.04.3.1.4
C4-derived polymers
Dehydration of bio-based isobutanol opens the value chain to C4 olefins such as isobutene and butadiene and to C4-derived biopolymers. As is well known from cracker-based chemistry, cationic chain polymerization of isobutene yields the homo polymer polyisobutene (PIB), while copolymerization of about 98% isobutene with about 2% isoprene yields butyl rubber. 1,3-Butadiene is homopolymerized by radical or anio nic chain polymerization to yield polybutadiene (BR) or copolymerized with other types of monomers such as styrene and acrylonitrile to yield styrene–butadiene rubbers (SBR) or acrylonitrile–butadiene–styrene (ABS) thermoplastics.
10.04.3.1.5
Polyisoprene
Isoprene, which can be obtained from the C5 platform, is also a high-value hydrocarbon. The immediate precursor to isoprene is isopentenyl diphosphate (IPP). Two biosynthetic routes to IPP have been described.2 Chain polymerization of isoprene leads to polyisoprene (PI) with different configurations; the most important for industrial applications is 1,4-cis-PI. The aim of some research is to synthesize natural rubber (NBR) from IPP. In 2010, collaboration between Genencor and the Goodyear Tire & Rubber Company resulted in a breakthrough technology for tires made from bioisoprene.
10.04.3.2
Thermoplastics Polyesters
10.04.3.2.1
General considerations
• A classification of both linear and cross-linked polymers may be based on the mechanism of the polymerization process. For polyester synthesis, two mechanisms of polymerization, polycondensation (Figure 14) and ROP (Figure 15), can be used: O R1
+ R2 OH
O
Catalyst
OH
R1
+ H2O OR2
Figure 14 Esterification reaction between an acid and a diol. O
O O
O
Initiator Catalyst
O
HO O
Glycolide
Figure 15 An example of ROP of a cyclic monomer.
H
n
71
The polycondensation synthesis of polyesters requires two steps and depending on the use of the diacid or the dimethyl ester of the diacid, two different industrial pro cesses are developed.64 For the first step of the diacid process, the diacid is prepolymerized with an excess of the diol (molar ratio = 1:1.05 to 1:1.2) at high temperature and under pressure. Acid groups are able to catalyze the reaction. Transesterification occurs during the second step, at high temperature and under vacuum to remove the excess of diol by distillation. To achieve high-molar-mass polymers, this step needs catalysts such as metal oxides (antimony, germanium, etc.), alkoxides (titanium, etc.), or acetates (lithium, magnesium, etc.). When the dimethyl ester of the diacid is used in the first step, a catalyst has to be introduced for interexchange reactions. • The ROP is an ionic chain polymerization initiated by strong bases such as metal alkoxides, thioureas, heterocyclic carbenes, or complexes of aluminum, zinc, tin, and lanthanides. Depending on the initiator and reaction condi tions, almost all conceivable mechanisms (cationic, anionic, coordination, etc.) have been proposed to explain the kinetics, side reactions, and nature of the end groups. The ROP allows a higher control of the reaction and remains the widely used method for the synthesis of well-defined materials. Degradation of polyesters is primarily due to hydrolysis of the ester linkages in the presence of water. On the contrary, drying conditions are recommended for processing of com mercial polyesters. When aliphatic polyesters are exposed to a humid environment following drying, moisture is quickly absorbed into the polymer up to its equilibrium level of swelling. Kinetics for melt hydrolysis depends on water con centration, acid or base catalysis, and polymerization catalyst concentration. In fact, many of the aliphatic polyesters can be rendered biodegradable. They are degraded to oligomers and monomers via hydrolysis and then metabolized to car bon dioxide and water. After use, this can be quite a facile process under standard industrial composting conditions, but it is worth noting that degradation is very slow at low temperatures. • Polyesters represent a large group of polymers that can lead to primarily partial substitution or full bio-based polymers. More particularly, aliphatic polyesters have received consid erable attention for applications in packaging, adhesives, coatings, and printing inks as well as in biomedical applica tions, such as resorbable surgical sutures for their favorable features that hydrolytic and/or enzymatic degradation pro ducts can be naturally metabolized into nontoxic substances as they are readily susceptible to biological attack.65 The bio-based aliphatic or cycloaliphatic α,ω-dicarboxylic acids such as succinic, fumaric, malic acids, and FDCA in combination with bio-based diols such as 1,2-PDO (from sorbitol or glycerol), 1,3-PDO (from glycerol, C3 platform); ethanediol (from ethylene, C2 platform), or isosorbide (from dehydration of sorbitol, C6 platform) (Figure 16) create new fully renewable polyesters. Typical monomers for ROP are
72
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
HO
H O
OH HO
OH
H3C
OH
OH
HO
O H
1,2-Propanediol
1,3-Propanediol
OH Isosorbide
1,2-Ethanediol
Figure 16 Formulas of some bio-based diols for polyester synthesis.
O
O
O
O O
O n
O O O
O
Lactide
Glycolide
γ-Butyrolactone Cyclic oligoesters
Figure 17 Typical cyclic monomers for ROP.
lactide, glycolide, γ-butyrolactone, and cyclic oligoesters (Figure 17).
10.04.3.2.2
Polylactide acid and polyglycolic acid
10.04.3.2.2(i) Scheme leading to polymers As described in the introduction, corn or sugar feedstocks are processed to yield D-glucose that is then fermented to yield lactic or glycolic acid. The lactic or glycolic acids can be ther mally and catalytically converted into their cyclic analogs, i.e. polylactic acid (see Chapter 10.12) and polyglycolic acid (PGA) (Figure 18). When a diol is used as initiator, the formed polymers are with terminal hydroxyl groups. 10.04.3.2.2(ii) PLA polymerization To proceed in reasonable conditions and afford polymers with controlled properties, many catalyst systems have been evalu ated for the ROP of lactide.66 Tin compounds, especially tin(II) bis-2-ethylhexanoic acid (tin octoate), are preferred for the bulk polymerization of lactide due to their solubility in molten lactide, high catalytic activity, and low rate of racemization of
the polymer. The ROP of L-lactide using an equimolar complex of 2-ethylhexanoic acid tin(II) salt, Sn(Oct)2, and triphenyl phosphine as catalyst shows a reactivity providing a polymerization propagation rate fast enough to imagine a continuous single-step reactive extrusion process for bulk poly merization.67 For some applications, one solution to the problem is to use biocompatible (i.e., nontoxic) initiators for lactide polymerization.
10.04.3.2.2(iii) PLA properties PLA exists in three isomeric forms: D, L, and racemic (D,L). PLA can be either amorphous or semicrystalline, depending on the stereochemistry and thermal history. For semicrystalline PLAs, both the glass transition temperature (Tg 58 °C) and melting temperature (Tm, 130–230 °C) (depending on structure) are important for determining the use temperatures. Both of these transitions (Tg and Tm) are strongly affected by the overall optical composition, primary structure, thermal history, and molar mass. The crystallization kinetics of PLA is rather low and strongly dependent on the optical copolymer composi tion.68 The slow crystallization rate means that PLA-extruded objects such as sheets and pellets are very often 100% amor phous after normal quenching operations. The cost performance balance of PLA has resulted in its use in many applications, including packaging, paper coat ing, fibers, films, and a host of molded articles. PLA is not being used in these applications solely because of its degradability nor because it is made from renewable resources. PLA can be used for not only short but also long-term applications.
O
OH
HO
O
HO
O
O
Lactic acid
OH
O O
n
High-molar-mass PLA Ring-Opening Polymerization (ROP)
Polycondensation –H2O
O O
HO O
O O n
O
OH Depolymerization O
O
O Lactide
Low-molar-mass PLA Mn ≈ 5000 g mol−1 Figure 18 Different steps for PLA production via prepolymer and lactide. (Same process for PGA via prepolymer and glycolide.)
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
10.04.3.2.2(iv) Polyglycolide PGA is a rigid thermoplastic material and is also produced by ROP of glycolide (the cyclic dimer of glycolic acid). It exhibits a higher crystallinity than does PLA (46–50%). The glass transi tion temperature is Tg 44 °C and the melting temperature is Tm 223 °C.69 PGA is not soluble in most organic solvents but has a high sensitivity to hydrolysis. Compared to PET, PGA displays better barrier properties to CO2 and O2. It can be processed by extrusion, injection, and compression molding, but its processing window between its melting and degradation temperatures is extremely narrow. The attractiveness of PGA as a biopolymer in medical applications is due to the fact that its degradation product, glycolic acid, is a natural metabolite.70
10.04.3.2.3
Aliphatic polyesters: poly(alkylene succinate)s
10.04.3.2.3(i) Polymerization • Poly(alkylene succinate)s can be made through the melt condensation process described above (Figure 14).71 Even in the presence of very effective transesterification catalysts and under high vacuum conditions, the preparation of high molar-mass poly(alkylene succinate)s with improved mechanical and processing properties remains synthetically challenging. A useful way to overcome the problem of incomplete polymerization and short chain length is to use so-called chain extension technology, usually carried out in the presence of coupling agents reacting with the reactive chain ends. Different types of chain extenders can be used: epoxies (reaction with –COOH chain ends), isocyanates, and carbonate or phosgene (reaction with –OH chain ends). • For other applications like coatings, α,ω-dihydroxy-terminated oligo(alkylene succinate)s have been prepared via the thermal polycondensation of excess diol and succinic acid. The molar mass of the products depends on the excess diol used, but as one target is to have liquid macrodiols at low temperature (see Section 10.04.3.3.2), it usually ranges between 900 and 4000 g mol−1. α,ω-Dicarboxy-terminated products have also been prepared using an excess of succinic acid. 10.04.3.2.3(ii) Properties and applications • Aliphatic polyesters have been recognized for their biode gradability and susceptibility to hydrolytic degradation. One of the most investigated biodegradable polyesters is poly (butylene succinate) (PBS). PBS is a flexible polymer (Tg –32 °C and Tm 110 °C) that can compete with PE but with a good printability and a good compatibility with other biodegradable polymers such as PLA or starch. • Initially, PBS was prepared from fossil feedstock, but obtain ing 1,4-BDO from bio-based succinic acid or directly from glucose fermentation would afford 100% bio-based PBS (Mitsubishi).41b • A new 100% bio-based polyester with an odd number of – CH2– groups in its diol monomer could be poly(trimethy lene succinate).72 • For aliphatic polyesters, it is known that chemical structure, molar mass, degree of crystallinity, spherulite size, and lamellar structure can influence the biodegradation rate.
73
Copolymers such as poly(ethylene-co-butylene succinate) or poly(butylene succinate-co-adipate) have lower thermal properties and (because of the lower cristallinity) exhibit higher biodegradation rates than do the homopolymers.72a • The high rigidity of isosorbide, a starch-derived diol, has been extensively exploited to enhance thermomechanical stability of polycondensates, such as polyesters.73 For exam ple, isosorbide-based polysuccinates with glass transition temperature Tg values in an appropriate range (45–65 °C) have been prepared. One advantage of powder coating applications of such fully aliphatic α,ω-hydroxyl- or car boxy-terminated low-molar-mass (2000 and 6000 g mol−1) polyesters is the absence of yellowing of the coating over time.74 However, the major difficulty for the use of isosor bide is still the control of the polyester functionality because of the low reactivity of the secondary hydroxyl group.
10.04.3.2.4
Poly(hydroxyl alkanoates)
10.04.3.2.4(i) Synthesis PHAs are a class of aliphatic polyesters produced via fermenta tion of renewable feedstocks. The main members of the PHA family (Figure 19) are those with x = 1 (for all commercially relevant polymers) and R variable: poly(3-hydroxybutyrate), P(3HB), with R = methyl; poly(3-hydroxyvalerate), P(3HV), with R = ethyl; poly(3-hydroxyhexanoate), P(3HHx), with R = propyl; poly(3-hydroxyoctanoate), P(3HO), with R = pentyl; poly (3-hydroxydecanoate), P(3HD), with R = heptyl; and the medium-chain-length poly(3HOd), with R = 15. Whereas production of PLA or PBS involves a two-stage process (fermentation to monomer followed by a conven tional polymerization step), PHAs are produced directly via fermentation of carbon substrate within the microorganism. Indeed, the PHA accumulates as granules within the cyto plasm of cells and serves as a microbial energy reserve material. However, PHA extraction requires large amounts of organic solvent after the fermentation step, which rises envir onmental and health concerns for industrial production. A wide range of PHA homopolymers, random copolymers, and terpolymers have been produced, in most cases at the labora tory scale.75 10.04.3.2.4(ii) Properties and applications PHA polymers have a semicrystalline structure with a rather high degree of crystallinity ranging from 40 to 80%. P(3HB) homopolymer is a stiff and brittle material. It has a melting temperature (Tm 180 °C) and mechanical properties (Young’s modulus and tensile strength) closed to those of PP. The elongation at break is, however, substantially lower than that of PP. The incorporation of hydroxyalkanoate
O HO
Figure 19 Structures of PHAs.
R H C O H2 x n
74
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
comonomers into a P(3HB) chain can greatly improve the mechanical properties of the material. Due to its high crystallinity (60–70%), P(3HB) displays excellent resistance to solvents and a relative resistance to hydrolytic degradation. It also exhibits good barrier properties. It can be processed as classic thermoplastics and melt spun into fibers, but one difficulty for the processing of films and plates is its low crystallization rate. Like other aliphatic polyesters, i.e., PLA and PBS, PHA has the potential for substitution in conventional applications. PHA is also a promising material for many novel applications including tissue engineering scaffolds, where biodegradability and the use of renewable feedstocks are prerequisites that conventional syn thetic thermoplastic polymers cannot meet.76 PHA technology ultimately goes back to the1970s and ‘80s, when ICI first devel oped Biopol PHA from naturally occurring bacteria. ICI’s patents were first bought by Monsanto and ultimately acquired by Metabolix. Metabolix and ADM in the United States and Kaneka in Japan are actually the front-runners for establishing commercial polyhydroxyalkanoate production.
10.04.3.2.5 Aromatic polyesters: poly(alkylene terephthalate)s 10.04.3.2.5(i) Polymerization Poly(alkylene terephthalate)s can also be made by the melt condensation process previously described. In this case, because of the high melting temperature of these aromatic polymers, solid-state polymerization (SSP) can be used during a third step to achieve high inherent viscosities. The product after the second step is essentially noncrystalline, but it can be made semicrystalline by heating the pellets to a temperature above the Tg for an extended period of time. This induces crystallization so that the polyester can then be heated to a higher temperature but below the melting temperature Tm to raise the molar mass during this third step. SSP is also a method suitable for the preparation of copolymers from polyconden sates with the retention of long homopolymer blocks. 10.04.3.2.5(ii) Properties and applications • Partially bio-based poly(trimethylene terephthalate) (PTT) produced from petrochemical terephthalic acid (or dimethyl terephthalate) in combination with bio-based 1,3-PDO (DuPont, USA) has Tg 55–70 °C and a Tm 225–228 °C, lower than the ones of poly(ethylene terephthalate) (PET). It can be said that PTT combines physical properties similar to PET (strength, stiffness, toughness, and heat resistance) with processing properties of poly(butylene terephthalate) (PBT) (low melt and mold temperatures, rapid crystallization, and faster cycle time compared to PET); it is also similar to PAs (PA6 and 6,6) and PP for fiber applications and is similar to polycarbonate (PC) for molding applications. In addition, PTT films have excellent barrier properties to carbon dioxide and water vapor compared to PET and PA films. • Once bio-based ethanediol and BDO (from succinic acid hydrogenation or from glucose fermentation) are available in sufficient quantities, it will also be possible to produce partially bio-based PET and PBT. • As explained before, the use of isosorbide offers enhanced material properties. Copolyesters of ethanediol, isosorbide,
and terephthalic acid (PEIT) have a higher glass transition temperature compared to PET and can therefore broaden the range of applications. Depending on the isosorbide content, amorphous PEIT copolyesters can have Tg 120–140 °C and can compete with other amorphous thermoplastics such as polyethylene terephtalate glycol (PETG), PC, PMMA, etc.73,77
10.04.3.2.6
Emerging polyesters
1. Poly(alkylene adipate)s are certainly the most common ali phatic polyesters. Bio-based poly(alkylene adipate) oligomers and polymers with the same properties are expected to be produced when the bio-based adipic acid is an industrial product.57,58 2. Polyesters based on FDCA.78–80 Aliphatic FDCA has a large potential as a replacement for aromatic terephthalic acid, a widely used component in various polyesters, PET, PEIT, PBT and PTT as explained above. An optimized process for the synthesis of FDCA monomer and for the production of polyesters with high molar masses and low coloration has been developed by Avantium, a spin-off from Royal Dutch Shell in 2010. 3. Poly(γ-butyrolactone). γ-Butyrolactone can be polymerized by ROP. Work has to be done to determine if the obtained α,ω-hydroxyl-terminated oligomers and high-molar-mass polymers can be used instead of petro-based poly (ε-caprolactone). 4. Poly(malic acid). Biodegradable malic acid-based polymers are interesting alternatives for biomedical and pharmaceuti cal applications such as polymeric matrices for drug delivery systems. Poly(malic acid) (PMA) has been reported to be synthesized by two approaches: ROP and direct polyconden sation. The ROP route is difficult because of the several steps involved (synthesis and then ROP of benzyl β-malolacto nate); in contrast, direct polycondensation is a very useful method for the synthesis of PMA with high molar masses.81
10.04.3.3 10.04.3.3.1
Polyurethanes (PUs) and Polyureas General considerations
The mechanism for isocyanate reactions consists in the nucleo philic addition of an active hydrogen (AH) compound to the electron-poor carbonyl atom of isocyanate (Figure 20). A broad range of hydrogen-containing nucleophiles react with both aromatic and aliphatic isocyanates. Reaction with poly alcohols gives PUs (–O–CO–NH–), while reaction with amines gives polyureas (–NH–CO–NH–). If the functionality of the hydroxy-containing compounds or the isocyanate is increased beyond 2, branched and possibly cross-linked polymers are produced.82 Because the nature of the polyol and isocyanate components can widely vary, PUs _
R
N C O + AH
O R N C+ A H
O R HN C A
Figure 20 Mechanism for isocyanate reaction with an AH compound.
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
are among the most versatile polymers producing a wide variety of materials (see Chapter 10.24). PU foams are prepared from basically the same raw materi als as elastomers. Instead of the chain extender, water is used, which reacts with isocyanates to form an amine and CO2, which results in foaming. The diamine thus created can then react with isocyanate groups, giving polyurea short segments.
10.04.3.3.2
Bio-based PUs
• So far, the isocyanate component (with the exception of one vegetable oil-derived fatty dimer diisocyanate) is exclusively derived from petrochemical feedstock. However, there are some results in the literature on the use of a furanic diiso cyanate monomer, derived from HMF.83 1,4-Butane diisocyanate (from C4 platform) has been used as building block for biomedical biocompatible PUs.84 • On the contrary, there are a lot of bio-based macrodiols, but most of them are from vegetable oil such as soybean oil, castor oil, sunflower oil, rapeseed oil, and their fatty acids (see Chapter 10.03). Other bio-based polyester macrodiols from carbohydrate feedstock such as α,ω-diol PBS, poly(butylene adipate) and copolymers, poly(alkylene-co isosorbide succinates), and poly(γ-butyrolactone) have been discussed in Section 10.04.3.2.3. • For polyether macrodiol, polyethylene oxide, polypropylene oxide and copolymers obtained by anionic polymerization of EO and propylene oxide, polytetrahydrofuran obtained by cationic polymerization, and also polytrimethylene ether obtained from 1,3-PDO (Cerenol™, DuPont) can be used as soft segments. Sucrose, sorbitol, and their derivatives have been used for a long time as short-chain polyether polyols for rigid foams. Physicochemical properties of the PU foams are improved when sucrose with its eight hydroxyl groups is first alkoxylated with ethylene or propylene oxide and the resulting polyether polyols are used for PU formation.85 • For chain extenders used for linear segmented PU synthesis, all the bio-based diols described for synthesis (Section 10.04.3.2.1) such as BDO, 1,2- and 1,3-PDOs, and isosorbide can be used.
10.04.3.4
Emerging Products
10.04.3.4.1
Bio-based polyamides (PAs)
1. Formation of amide linkages: –CONH– As for polyesters, two pathways, polycondensation (step-growth polymerization with water as side product, Figure 21) and ROP, can be used for PA synthesis. The different PAs are identified by numbers denoting the number of carbon atoms in the monomers (diamine first for the diamine + diacid, A2B2 type).
O
O R1
OH
+ R2 – NH 2
R1
NHR2
Figure 21 Reaction between an acid and a diamine.
+ H2O
75
2. No bio-based PAs from carbohydrate feedstock are commer cially produced at the present time, but some may emerge by using the following: • diacids previously described for the synthesis of bio-based polyesters synthesis; • diamines such as 1,4-butane diamine (obtained from succinic acid) or 2,5-bis(aminomethyl)tetrahydrofuran (prepared from FDCA, Figure 13); • caprolactam, the monomer for PA6, which may be pro duced in future by fermentation from glucose, via the precursor lysine;86 • the reaction of glutaric acid and a diamine that would lead to polyhydroxypolyamide but with unknown properties. 3. Expected properties for these new PA: • PA44 based on 1,4-butane diamine and succinic acid, PA4n based on 1,4-butane diamine, and PAn4 based on succinic acid have been manufactured on the laboratory scale.33b These PAs show interesting and unexpected properties. For example, PA24 possesses the same properties as both silk proteins and commercial PAs. PA46 (Stanyl®) with a melting point of 280 °C is a commercial product from DSM; • The properties of polyesters can be improved by the intro duction of amide groups into the main chain; poly(ester amide)s based on succinic acid, BDO, and 1,4-butanediamine can be synthesized for biodegradable properties; • Polyaspartates (from the L-aspartic acid chemistry) are acidic PAs and have been commercialized by Bayer.87
10.04.3.4.2
Multisegmented block copolymers/TPEs
Aiming at generating materials exhibiting properties similar to linear segmented PUs and by using polyesters or PA chemis tries, multisegmented polyether–ester (PE-b-E) and polyether– amide (PE-b-A) have been prepared. They are proposed for automotive, shoe, medical, and wire and cable applications. DuPont has made thermoplastic polyester elastomers con taining 20–37% b.w of bio-based material by using a polyol, CerenolTM (produced by direct polymerization of bio-based 1,3-PDO), as elastomeric soft segment instead of the classical polytetrahydrofuran macrodiol. Partially bio-based thermo plastic PA elastomers from Arkema with PA11 hard segments are available and it is easy to imagine a 100% bio-based poly ether–amide by the use of the soft Cerenol polyether segment with PA11 as rigid segment.
10.04.3.4.3
(Meth)acrylic acid and (meth)acrylate families
1. Poly(meth)acrylic acid and poly(meth)acrylates are an important family of polymers for a lot of applications, such as paints, coatings, or ‘acrylic glass’. Polymers are obtained by free-radical chain polymerization of (meth) acrylic acid or (meth)acrylate monomers. As all the (meth) acrylates monomers can be prepared from (meth)acrylic
76
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
acids, the main point is the preparation of bio-based (meth) acrylic acid. 2. Acrylic acid can be obtained from 3-HPA platform chemi cals through fermentation (via dehydration) or from levulinic acid or glycerol building blocks.
PC is produced via the phosgene process, where CO and chlorine are combined to form phosgene (carbonyl dichlor ide, COCl2). Recently, the development and industrialization of a novel process for producing high-quality PC using CO2 as starting material without using highly toxic phosgene has been proposed.91 BPA polycarbonate is a versatile, tough plastic used for a variety of applications, from bulletproof windows to com pact discs (CDs) or eyeglasses. It can crystallize, but in practice it is an amorphous thermoplastic with a Tg 150 °C that flows above about 300 °C. Injection mold ing is more difficult than other common thermoplastics owing to its non-Newtonian flow behavior. The main advan tage of PC over other types of thermoplastic is unbeatable strength combined with light weight, excellent transparency, durability, and rather high refractive index (1.60). However, it exhibits poor solvent resistance and low scratch resistance. • Poly(aliphatic carbonate)s display promising characteristics; they have a better biodegradability than does the aromatic PC and could be employed to develop specialty thermoplas tics or polycarbonate diols (PCDL) as soft segments in PU elastomers: – PCDL prepared via the transesterification of alkylene car bonates with aliphatic diols such as 1,6-hexanediol are hydroxy terminated and typically possess molar masses in the range of 1000–5000 g mol−1 (Figure 22(a)).92 The
A newly discovered enzyme makes it possible to turn a linear C4 carbon structure into a branched one. Compounds of this type are precursors of methyl methacrylate monomer.88 Recently, biomass-based monomer precursors of poly (methacrylic acid) (PMA) and PMMA were reported to be obtained from the thermal degradation of a bio-based poly (tetramethylene glycolide) (PTMG).89 Also known as methyl succinic acid, itaconic acid (Figures 2 and 4(d)) is a five-carbon dicarboxylic acid. It is currently produced by fermentation of glucose or saccharose and is used as a specialty monomer. Itaconic acid is frequently used as comonomer in vinyl and acrylic latex recipes to improve colloidal stability.90
10.04.3.4.4
Polycarbonates
10.04.3.4.4(i) General considerations • Polycarbonates with –OCO2– linkage can be divided into poly(aromatic carbonate)s and poly(aliphatic carbonate)s. An aromatic PC based on 2,2-bis(4-hydroxyphenyl)propane (commonly called bisphenol A, BPA) and usually abbre viated as PC is the most widely used engineering thermoplastic in various applications. The vast majority of
(a)
O
(n + 1) HO R OH
+ n H3CO
O OCH3
HO
O
R
O R
OH + 2n CH3OH n
(b)
R
R
O ROP
n O
O
H
O
O R
O
OH R
R
R
n–1
O
R = H, CH3
(c)
O O
O O
LIPASE
O
O
70 °C, bulk
(d)
O
O + CO2
CHO
n Poly(TMC)
Trimethylene carbonate (TMC)
O
lonic lnitiator Catalyst
O n Poly(cyclohexene carbonate) PCHC
Figure 22 Different routes to the synthesis of aliphatic PCs: (a) transesterification of alkylene carbonates with aliphatic diols; (b) classic ROP of cyclic carbonates; (c) ROP of cyclic carbonates with the help of a lipase; and (d) alternating copolymerization of epoxides with carbon dioxide (CO2).
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
main advantage of PUs containing oligocarbonate soft segments is their higher hydrolytic stability than that of conventional polyester-based PUs (the hydrolysis of car bonate linkages does not produce the acidic groups that catalyze the hydrolytic degradation of ester bonds). – Another route for aliphatic PC synthesis is the ROP of cyclic carbonates by a base catalyst (Figures 22(b) and 22(c)). One side reaction is decarboxylation and as a consequence, the formation of ether linkages.93 It can be limited by the choice of a selective catalyst. – The last synthesis method is the alternating copolymeriza tion of epoxides, such as propylene oxide, with carbon dioxide (CO2) (Figure 22(d)). The CO2/epoxy copolymer synthesis, which is one of the most promising processes for CO2 utilization, can use propylene oxide from glycerol. The reaction needs an ionic initiator, but owing to the kinetic stability of carbon dioxide, it also requires the use of a cocatalyst.94 The CO2/propylene oxide copolymer has interesting properties: the copolymer burns gently in air without emitting toxic volatiles, it adheres strongly to a cellulosic substrate, and the barrier properties for O2 and water are rather good. Commercial products are from Novomer and recently from Bayer. Unfortunately, the scope of this polymer is presently limited by its low Tg 40 °C. A higher Tg is required to allow the use of these CO2 base alternating copolymers as structural mate rials. It explains the use of cyclohexene oxide (Tg of the copolymer 115 °C) instead of propylene oxide. 10.04.3.4.4(ii) Bio-based PCs While most of used PCs are derived from petroleum, the con version to bio-based PC is certainly reachable: • Trimethylene carbonate (TMC), a cyclic monomer, can indeed be obtained by reacting diethyl carbonate with bio-based 1,3-PDO and then polymerizing by ROP of TMC in the presence of diethyl zinc or triethyl aluminum or lipases.95 • Transesterification of alkylene carbonates can be carried out in the melt with isosorbide or 1,3-PDO and a catalyst to obtain bio-based aliphatic PCs.96 • But the more important bio-based engineering thermoplastic is certainly the isosorbide-based bio-PC proposed by Mitsubishi Chem (2010). This new biopolymer is produced without solvent by melt transesterification process and pre sents the advantage of low energy consumption. Compared to BPA-PC and PMMA, it shows high transparency, extremely good UV light resistance and very unique optical properties and low birefringence, relatively good heat (Tg 130 °C), and multiaxial impact resistance.97 Several patents from other companies have been published in 2010, which con firm that this polymer has attractive properties.98
10.04.3.4.5
Furan resins
In the presence of an acid catalyst (such as a mineral acid or BF3), furfuryl alcohol (formula in Figure 9) undergoes
77
autocondensation (methylolation) to produce liquid linear oligomers consisting of furan rings linked by methylene bridges. The chemistry and applications of furan resins are well known and have even lost market volume at the end of the last century. They are primarily employed for foundry sand cores and molds for casting metal parts. There are still some commercial products such as BioRez resin from TransFurans Chemicals. Recently, it was shown that linear oligomers of furan could be used as organic semiconductors with field effect mobilities similar to those of the corresponding thiophene analogs.99
10.04.3.4.6
Unsaturated polyesters, UP thermosetting resins
10.04.3.4.6(i) Thermosetting polyesters Network formation distinguishes polyester resins from linear (thermoplastic) polyesters such as those in Section 10.04.3.2 (PBS, PBT, PET, etc.). Cross-linking can be achieved by use of polyols such as glycerol, as in the case of saturated polyesters named glyptal. Glyptal, which is used mainly as an adhesive or modified with natural or synthetic oils (oil-modified alkyds) for coatings, is formed by the reaction of glycerol and phthalic anhydride. But most of cross-linked polyesters are obtained from unsaturated polyester precursors. When an excess of maleic anhydride or a mixture of maleic anhydride and other anhydride (particularly phthalic anhy dride) or unsaturated diacids (like fumaric acid) are reacted with aliphatic diols, low-molar-mass UPs are formed. Products having molar masses around 1000–2000 g mol−1 are generally diluted with a liquid vinyl monomer, most often styrene. Such a reactive mixture called ‘UP resin’ can be transformed into cross-linked polymers through a free-radical chain copolymer ization between the styrene and the maleate/fumarate double bonds. Cured UP resins are rigid materials used as matrices for glass fiber composites; the products are called sheet or bulk molding compounds (SMCs or BMCs).82 Another family of an UP resin called vinyl-ester, VE resins is obtained through the reaction of an epoxy monomer with methacrylic acid or the reaction of an isocyanate oligomer with hydroxylethyl methacrylate. These VE resins are also dis solved in styrene. 10.04.3.4.6(ii) Bio-based UP prepolymers As the aim is to prepare bio-based UP prepolymers, all the diacids and diols previously described (Section 10.04.3.2.4) can be used. Rigid phthalic anhydride units can be replaced by FDCA or by the use of a rigid diol like isosorbide. Since the generation of UP resins also needs double bonds on the back bone, fumaric acid and itaconic acid have been proposed.100 For VE prepolymers, the bio-based epoxy backbones are discussed in the next section and for PUs, backbones are dis cussed in Section 10.04.3.3.2. 10.04.3.4.6(iii) Bio-based reactive diluents As said, UP or VE prepolymers are dissolved in a reactive diluent such as styrene. Since the commercial inception of UP resins, styrene has been a primary reactive diluent due to its low cost, availability, ease of use, and resulting excellent mechan ical properties. However, in recent years, government regulations have restricted styrene emissions in open molding facilities due to harmful environmental and health effects. Accordingly, in addition to renewable (or recycled) raw
78
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
CH3 O
O O
CH3
CH3
OH
O
O
O CH3
n
Figure 23 Formula of DGEBA with different degrees of polymerization, n.
materials, the UP resin industry has a need to offer styrene-free and volatile organic compound (VOC)-free UP resins. Different dimethacrylate monomers of BDO or 1,3-PDO (which could be bio-based) and itaconate esters have been tested with some success.101
10.04.3.4.7
Thermosetting epoxy resins
Cross-linked epoxies exhibit outstanding properties that have placed them as the standard option for a variety of applications such as adhesives, paints, coatings, and composites for struc tural applications.82 A major type of epoxy monomers is derived from the reaction of bis(4-hydroxy phenylene) 2,2-propane (called BPA) and 1-chloropropene 2-oxide (called epichlorohydrin) in the presence of sodium hydroxide (con densation reaction). The structure of the major product, diglycidyl ether of bisphenol A (DGEBA), and its condensed forms (Figure 23) is dependent upon the stoichiometry of the reaction. Amines are the most commonly used curing agents/hard eners for epoxides. The polyaddition reaction involves epoxy groups reacting with primary and secondary amines. One epoxy ring reacts with each amino proton. The epoxy–phenol reaction needs to be activated by some catalysts such as imida zole. The epoxy–acid reaction proceeds through a more complex polyaddition mechanism with some side reactions (transreaction and acid–alcohol reactions). But epoxy monomers are very versatile molecules and they can react with both nucleophilic and electrophilic species. Thus, both Lewis acids and bases are able to initiate the ionic chain polymerization of epoxy precursors. The chain polymer ization of difunctional epoxy monomers leads to networks. They can also copolymerize with cyclic anhydrides, initiated by Lewis bases. After the amines, acid anhydrides constitute the next most commonly used reagents for curing epoxy monomers.
prepolymers have been prepared and tested.102,103,104 Another route is the enzymatic epoxidation of cardanol.105 However, “bio-phenol” is a still missing building block and more generally, modified aromatic-based epoxy prepolymers would be desirable because of the classification of BPA as CMR R3 substance, even more so, as the discussion around the endocrine potential of BPA has entered the greater public. 4,4-bis-(4’-hydroxyphenyl)pentanoic acid can be a candidate. Also called diphenolic acid, DPA is prepared by the reaction of levulinic acid with two molecules of phenol. Levulinic acid is believed to be a cheap platform chemical and can be commer cially produced from cellulose-rich biomass (especially from waste biomass) in large scale.2,106 It may be a direct replace ment for BPA not only in epoxy resins but also polycarbonates, polyarylates and other polymers. It contains a carboxyl group, absent from BPA, which confers an additional functionality that could be useful in polymer synthesis. Another route, i.e. using natural polyphenols, and more specifically con densed tannins that can be extracted from wastes produced by the wood and wine industries and their molecular subunits such as catechin, resorcinol and/or 4-methylcatechol offers other possibilities.107 10.04.3.4.7(ii) Bio-based hardeners Bio-based diamines, diacids, and acid anhydrides have been discussed in previous section. New bio-based multifunctional amines can be also prepared by degradation of chitosan. Aromatic diamines are used in formulations for structural composites; their replacement by bio-based hardeners can be a problem, which can be solved eventually by the use of bio-based phenols from lignin or by phenalkamines from cardanol.103a,104
10.04.4 Conclusions 10.04.4.1
10.04.3.4.7(i) Bio-based epoxy monomers There is not yet an easy access at the horizon to the production of epoxy monomers from renewable resources. Nonetheless, a significant carbon food-print reduction (30 wt. %) can be expected when using epichlorhydrin, ECH generated from bio-based glycerol (Epicerol® - process, Solvay; GTE-process, DOW) and bio-acetone (which can be industrially produced through the anaerobic fermentation of corn by the Acetone Butanol Ethanol fermentation (ABE process) using the Weizman Organism Clostridium acetobutylicum, ATCC 824). Nevertheless, by reacting epichlorohydrin with sorbitol (com mercial products from Nagase ChemteX or JSI Co), isosorbide, phenols extracted from lignin, or by one pot reaction of furfural with trimethylsulfonium iodide in a basic aqueous medium leading to 2-furyloxirane, new 100% biobased epoxy
Specificity of Bio-Based Polymers
Some of the polymers discussed in this chapter are already produced at large-scale facilities or their industrial productions have been announced. Other polymers need some technical breakthrough development before being produced in the next few years. Difficulties can come from technical challenges. One concerns the polymerization methods. As mentioned in this chapter, most of the carbohydrate bio-based polymers are pre pared by polycondensation. Because transparent and colorless bio-based materials are highly desirable for a lot of applica tions, polymer synthesis must be performed at low temperature, which requires the development of very active catalysts. Another technical challenge is that most of the carbo hydrate bio-based polymers (except polyolefins) are generally more thermally, chemically, hydrolytically, and oxidatively sensitive as compared to petrochemical-derived materials. For
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
O O
O
O
O
O Diglycidyl ether of isosorbide O
O
O
O O
O
O O
O
O
O
HO
R
O O
H
O O
O O
O R
OH
O
O
O Diester for plastisizing of PVC and other polymers
H
N H
O
O
Isosorbide
O
n
Polycarbonate of isosorbide
n Aliphatic polyester:
poly(isosorbide succinate)
79
O
O
N H
O O
n Polyurethane with isosorbide as chain extender
O O
O O O
O O n Aromatic polyester: polyethylene-co-isosorbide terephtalate
Figure 24 Different uses of isosorbide (the diisocyanates based on isosorbide are missing).
this reason, one central challenge in their utilization is that they need to be totally reformulated and the processing industry also has to take care of experimental processing conditions.
10.04.4.2
Commodity and Engineered Materials
At the present time, polymers based on renewable materials have found extensive use in the packaging sector, but these materials in the future are expected to increasingly emerge in more components for high-performance applications. Economic difficulties can be overcome more easily when the bio-based precursor converts to the resulting materials with high Tg, optical properties, nontoxicity, and so on. And if so, it is not surprising that the bio-based monomer will rapidly find a lot of applications, as summarized in Figure 24 for the case of isosorbide.73,104,108 In this context, bio-based succinic acid and derivatives and also furan derivatives undoubtedly show great promise in industrial developments.
10.04.4.3
to improve some properties such as the gas barrier of PLA films and also to maintain the stiffness and tensile modulus of toughened polylactide.68 Other examples have been given for epoxy networks in Reference 103. • While carbon dioxide is not plant derived, the direct utiliza tion of this molecule as a C1 source and for the production of polymers could be critically important, given its widespread abundance. The use of CO2 as a monomer in polymer synth esis is not new (aliphatic PC, Section 10.04.3.4.4). But more important seems the fact that recent publications propose the direct synthesis of a monomer like isoprene through the basic equation of photosynthesis: CO2 + H2O and light and with the help of bacteria.109 The final conclusion has to be optimistic: with the help of ‘White biotechnology’,110 macromolecular chemistry, and materials science, polymers from renewable resources and especially the ones coming from carbohydrate chemistry will play an ever increasing role in our life.
Future of Polymers from Renewable Resources
The future of polymers from renewable resources can be stated in two additional points: • The development of nanotechnology offers new opportu nities to improve bio-based polymer properties. For example, a number of researchers have developed polylactide-based nanocomposite materials: PLA/organically modified layered silicate nanocomposites by melt extrusion
References 1. (a) Wolf, O., Ed. Report of the Institute for Prospective Technological Studies: Techno-Economic Feasibility of Large-Scale Production of Bio-Based Polymers, European Commission reference EUR 22103 EN, 2005. (b) Werpy, T.; Petersen, G., Eds. Top Value Added Chemicals from Biomass: Vol. 1—Results of Screening for Potential Candidate from Sugars and Synthesis Gas, US Department of Energy, Office of Scientific and Technical Information, National Renewable Energy Laboratory No. DOE/GO-102004-1992, 2004. www.osti.gov/bridge. (c) Patel, M.; Crank, M.;
80
2. 3. 4. 5. 6.
7. 8. 9. 10.
11. 12. 13. 14. 15. 16. 17. 18.
19.
20. 21.
22.
23.
24. 25. 26. 27.
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
Dornburg, V.; et al. 5th European BREW Final Report: Medium and Long-Term Opportunities and Risks of the Biotechnological Production of Bulk Chemicals from Renewable Resources – The Potential of White Biotechnology; European Commission’s GROWTH Program, 2006. (d) Kamm, B.; Kamm, M. Adv. Biochem. Eng. Biotechnol. 2007, 105, 175. (e) Shen, L.; Haufe, J.; Patel, M. K. Product Overview and Market Projection of Emerging Bio-Based Plastics, Commissioned by European Polysaccharide Network of Excellence and European Bioplastics; Final report June 2009. (f) U.S. Biobased Products: Market Potential and Projections Through 2025. www.usda.gov/oce/reports/energy/index.htm, 2008. (g) Belgacem, M. N.; Gandini, A., Eds. Monomers, Polymers and Composites from Renewable Resources; Elsevier: Amsterdam, The Netherlands, 2008. (h) Gandini, A. Macromolecules 2008, 41 (24), 9491. Bozell, J. J.; Petersen, G. R. Green Chem. 2010, 12, 539. Morschbacker, A. Polym. Rev. 2009, 49 (2), 79. Dinjus, R.; Arnold, U.; Dahmen, N.; et al. In Sustainable Solutions for Modern Economies; Höfer, R., Ed.; RSC Publication: Cambridge, UK, 2009. Bigorra, J.; Höfer, R. Comunicaciones; 38 Jornadas CED: Barcelona, Spain, 2008; p 179. (a) Zaldivar, J.; Nielsen, J.; Olsson, L. Appl. Microbiol. Biotechnol. 2001, 56, 17. (b) Martínez, A. T.; Ruiz-Dueñas, F. J.; Martínez, M. J.; et al. Curr. Opin. Biotechnol. 2009, 20, 348. (c) Kazmi, A.; Kamm, B.; Henke, S.; et al. In Introduction to Advanced Oil Crop Biorefineries; A. Kazmi Ed.; RSC Publications: Cambridge, UK; 2012, pp 1–47. (a) de Vasconcelos, J. N.; Lopes, C. E.; De França, F. P. Braz. J. Chem. Eng. 2004, 21 (3), 357. (b) Ochoa Cáceres, S. M. Dissertation, TU Berlin, 2010. Berg, C. World Ethanol Production and Trade to 2000 and Beyond. http://www. distill.com/berg/ (accessed August 10, 2010). Kochar, N. K.; Merims, R.; Padia, A. S. Chem. Eng. Prog. 1981, 66, 66–70. (a) Le Van Mao, R.; Nguyen, T. M.; McLaughlin, G. P. Appl. Catal. 1989, 48, 265. (b) Le Van Mao, R.; Dao, L. H. U.S. Patent 4,698,452, 1986 (Institut National de la Recherche Scientifique, Sainte-Foy/CA). Bia, J.; Guo, X.; Liua, M.; et al. Catal. Today 2010, 149 (1–2), 143. Chen, G.; Li, S.; Jiao, F.; Yuan, Q. Catal. Today 2007, 125 (1–2), 111. Bronnenmeier, K. From Fossil-To Bio-Based Refineries. http://www.biorefinica.de/ Vortrag%20Bronnenmeier.pdf (accessed September 12, 2010). John, R. P.; Nampoothiri, K. M.; Pandey, A. Appl. Microbiol. Biotechnol. 2007, 74, 524. Hause, B.; Rajgarhia, V.; Suominen, P. WO 2003/102152 (Cargill)., Dec. 2003, Burch, R. R.; Laffend, L. A.; Nagarajan, V.; Nakamura, C. U.S. Patent 7,169,588, 2007 (DuPont). Soucaille, P. WO 2008/052595 (Metabolic Explorer), May 2008. (a) Olivier, F.; Rousseaux P.; WO 2009/068110, 2009 (Metabolic Explorer). (b) Kurian, J. V. A New Polymer Platform for the Future – Sorona® from Corn Derived 1,3-Propanediol. J. Polym. Environ. 2005, 13 (2), 159–167. (c) Tao, J.; Kazlauskas, R., (Eds.) Biocatalysis for Green Chemistry and Chemical Process Development, John Wiley & Sons, Hoboken, 2011. (a) Werpy, T.; Frye, J. G., Jr.; Zacher, A. H.; Miller, D. J. WO 03/035582, 2000 (Batelle). (b) Chaminand, J.; Djacovitch, L.; Gallezot, P.; et al. Green Chem. 2004, 6, 359. Voelker, F.; Figge R.; Soucaille P.; WO 2010/51849 (Metabolic Explorer). May 2010. (a) Donaldson, G. K.; Eliot, A.C.; Flint, D.; et al. WO 2007/050671, 2006 (DuPont). (b) Peters, M.W.; Meinhold, P.; Buelter, T.; Landwehr, M. WO 2008/013996, 2007 (Gevo). (c) Atsumi, S.; Hanai, T.; Liao, J. C. Nature 2008, 451, 86–89. (d) Peters, M.; Liao, J. C.; Atsumi, S.; et al. WO 2008/098227, 2008 (Univers. California). (e) Evanko, W. A.; Eyal, A. M.; Glassner, D. A.; et al. WO 2009/086391, 2008 (Gevo). (f) Buelter, T.; Meinhold, P.; Feldman, R. M. R.; et al. WO 2010/ 051527, 2009 (Gevo/CIT). (a) Nimcevic, D.; Gapes, J. R. J. Mol. Microbiol. Biotechnol. 2000, 2 (1), 15–20; (b) De Guzman, D., http://www.icis.com/blogs/green-chemicals/2011/07/cathay industrial-biotech-file.html (retrieved 20.01.2012); (c) De Guzman, D. http://www.icis.com/Articles/2011/12/05/9513406/green-chemicals-growing number-of-chemical-firms-enter-bio-butanol.html (retrieved 20.01.2012) (a) Ramey, D. E. US Patent 5,753,474, 1996 (Environmental Energy); (b) Kraemer, K.; Harwardt, A.; Bronneberg, R.; Marquardt, W. In 20th European Symposium on Computer Aided Process Engineering – ESCAPE20; Pierucci, S., Buzzi-Ferraris, G., Eds.; Elsevier: Oxford, 2010. Peters, M.; Taylor, J.; Henton, D. E.; Manzer, L. E. WO 2010/099201, 2009 (Gevo). Smith, K. M.; Cho, K.-M.; Liao, C. Appl. Microbiol. Biotechnol. 2010, 87 (3), 1045. West, R. M.; Braden, D. J.; Dumesic, J. A. J. Catal. 2009, 262 (1), 134–143. (a) Chauvel, A.; Lefebvre, G. Petrochemical Processes; Institut Français du Pétrole/ Technip: Houston, TX, 1989. (b) Weissermel, K.; Arpe, H.-J. Industrial Organic Chemistry; Wiley: Hoboken, NJ, 1997.
28. Marliere, P. WO 2010/001078, 2010 (Global Bioenergies). 29. Lohbeck, K.; Haferkorn, H.; Fuhrmann, W.; Fedtke, N. Ullmann’s Encyclopedia of Industrial Chemistry; VCH: Weinheim, Germany, 1990; Vol. A16, p 53. (b) Haddad, M. S. U.S. Patent 6,103,935, 1999 (BP Amoco). 30. Ningjun, C.; Jianxin, D.; Gong, C. S.; Tsao, T. Appl. Environ. Microbiol. 1996, 62 (8), 2926. 31. Zeikus, J. G.; Jain, M. K.; Elenkovan, P. Appl. Microbiol. Biotechnol. 1999, 51 (5), 545. 32. Lee, S. Y.; Lee, P. C.; Hong, S. H.; Chang, H. N. Appl. Microbiol. Biotechnol. 2002, 58, 663. 33. Song, H.; Lee, S. Y. Enzyme Microb. Technol. 2006, 39, 352. (b) Bechthold, I.; Bretz, K.; Kabasci, S.; et al. Chem. Eng. Technol. 2008, 31 (5), 647. (c) Cukalovic, A.; Stevens, C. V. Biofuels Bioprod. Bioref. 2008, 2, 505. 34. Stokes, J. L. J. Bacteriol. 1949, 57, 147. 35. (a) Donelly, M.; Millard, C. S.; Stols, L. U.S. Patent 5,770,435, 1995 (Univers. Chicago). (b) Sanville-Millard, C.; Chao, Y.-P.; Liao, J. C.; Donelly M. Appl. Environ. Microbiol. 1996, 62 (5), 1808. (c) Nghiem, N. P.; Donelly, M.; Millard, C. S.; Stols, L. WO 98/33930, 1997 (Lockheed Martin Energy Res./Univ. Chicago). (d) Nghiem, N. P.; Donelly, M.; Millard, C. S.; Stols, L. EP 1,012,323, 1998 (Batelle/Univ. Chicago Argonne). (e) Donnelly, M. I.; Sanville-Millard, C.; Chatterjee, R. U.S. Patent 6,159,738, 1998 (Univ. Chicago). (f) Nghiem, N. P.; Donnelly, M.; Sanville-Millard, C. Y. WO 2004/043881, 2002 (Batelle). (g) San, K. -Y., Bennett, G. N.; Sanchez, A. U.S. Patent 2005/0042736, 2004 (Rice Univ.). (h) Sánchez, A. M.; Bennett, G. N.; San, K.-Y. Metab. Eng. 2005, 7 (3), 229. (i) Shanmugam, K. T.; O’Neil, L.; Patel, A.; et al. U.S. Patent 2005/0250192 (Univ. of Florida). (j) San, K. Y.; Bennett, G. N.; Sánchez, A. U.S. Patent 7,223,567, 2006 (Rice Univ.). (k) Dehey, F.; Segueilha, L.; Calande, O.; Varlamoff, C. WO 2009/081012, 2008 (Roquette). (l) Caulier, B.; Segueilha, L. WO 2010/092304, 2010 (Roquette). 36. Roa Engel, C. A.; Straathof, A. J. J.; Zijlmans, T. W.; et al. Appl. Microbiol. Biotechnol. 2008, 78 (3), 379. 37. Datta, R.; Glassner, D. A.; Jain, M. K.;Vick Roy, R. U.S. Patent 5,168,055, 1989 (Michigan Biotech./Emerald Bioagriculture/CPC Internat.). 38. Hong, Y. K.; Hong, W. H.; Chang, H. N. Biotechnol. Lett. 2000, 22, 871. (b) Jun, Y.-S.; Lee, E. Z.; Huha, Y. S.; et al. Biochem. Eng. J. 2007, 36, 8. 39. Orjuela, A.; Yanez, A. J.; Vu, D. T.; et al. Fluid Phase Equilib. 2010, 290, 63. 40. (a) Jansen, M.; Verwaal, R. WO 2010/003728, 2010 (DSM). (b) van den Tweel, W. Speciality Chem. Mag. Nov. 2010, 30. 41. (a) Schnabel, R.; Weitz, H. -M. EP 169,396, 1985 (BASF). (b) Gosch, H.-J.; Rust, H.; Fischer, R.; et al. EP 0557786, 1993 (BASF). (c) Burk, M. J.; Van Dien, S. J.; Burgard, A.; Niu, W. WO 2008/115840 A2, 2008 (Genomatica). 42. Wittcoff, H.; Reuben, B. G.; Plotkin, J. S. Industrial Organic Chemicals, 2nd ed.; Wiley: Hoboken, NJ, 2004. 43. Eppelmann, K.; Nossin, P. M. M.; Raeven, L. J. R. M.; et al. WO 2006/005603 and WO 2006/005604, 2005 (DSM). 44. (a) Hayes, D. J.; Fitzpatrick, S.; Hayes, M. H. B.; et al. In Biorefineries – Industrial Processes and Products; Kamm, B., Gruber, P. R., Kamm, M., Eds.; Wiley-VCH: Weinheim, Germany, 2006; Vol. 1 (7), pp 139–164. (b) Rackemann, D. W.; Doherty, W. O. S. Biofuels, Bioproducts and Biorefining, March/April 2011, 5 (2), 198–214. 45. (a) Connor, M. R.; Liao, J. C. Appl. Environ. Microbiol. 2008, 74 (18), 5769. (b) Cann, A. F.; Liao, J. C. Appl. Microbiol. Biotechnol. 2008, 81 (1), 89–98. (c) Connor, M. R.; Atsumi, S. J. Biomed. Biotechnol. 2010, DOI: 10.1155/2010/ 541698. 46. (a) Estrine, B. First International Conference on Renewable Resources and Biorefineries, Ghent, 2005. http://www.rrbconference.ugent.be/presentations/ Estrine%20Boris.pdf (accessed November 23, 2010). (b) Martel, F.; Estrine, B.; Plantier-Royon, R.; et al. Top. Curr. Chem. 2010, 294, 79–115. 47. Nikolaidou, Z.; Schöenicke, P.; Rogut, Y.; et al. 17th European Biomass Conference & Exhibition, Hamburg, 2009. http://www.chimarhellas.com/wp-content/uploads/ 2009/08/biomass-2-july-low.pdf BIOSYNERGYWorkshop_Hamburg_2July2009.pdf (accessed September 23, 2010). 48. Hill, K.; Höfer, R. In Sustainable Solutions for Modern Economies; Höfer, R., Ed.; RSC Publication: Cambridge, UK, 2009, pp 167–237. 49. Frenzel, S.; Peters, S.; Rose, T.; Kunz, M. In Sustainable Solutions for Modern Economies; Höfer, R., Ed.; RSC Publication: Cambridge, UK, 2009, pp 264–299. 50. Chheda, J. N.; Huber, G. W.; Dumesic, J. A. Angew. Chem. Int. Ed. 2007, 46, 7164. 51. Queneau, Y.; Jarosz, S.; Lewandowski, B.; Fitremann, J. Adv. Carbohydr. Chem. Biochem. 2007, 61, 217. 52. (a) Ellis, J. M. H.; Lewis, J. J.; Beattie, R. J., Manufacture of fatty acid esters of sorbitan as surfactants, US Patent 6,362,353, 1999 (ICI). (b) Hill, K.; Le HenFerrenbach, C. In Sugar-Based Surfactants for Consumer Products and Technical Applications; Ruiz, C. C., Ed.; Surfactant Science Series; CRC Press: Boca Raton, FL, 2009; Vol. 143, p 1.
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
53. Riva, S.; Chopineau, J.; Kieboom, A. P. G.; Klibanov, A. M. J. Am. Chem. Soc. 1988, 110, 584. 54. (a) Albertin, L.; Kohlert, C.; Stenzel, M.; et al. Biomacromolecules 2004, 5 (2), 255. (b) Kitagawa, M.; Tokiwa, Y. Carbohydr. Polym. 2006, 64 (2), 218. (c) Rodrigues Borges, M.; Alves dos Santos, J.; Viaira, M.; Balaban, R. Mater. Sci. Eng., C 2009, 29 (2), 519. 55. (a) Griffin, W. C. J. Soc. Cosmet. Chem. 1949, 1, 311. (b) Griffin, W. C. J. Soc. Cosmet. Chem. 1954, 5, 259. (c) Orafidiya, L. O.; Oladimeji, F. A. Int. J. Pharm. 2002, 237 (1–2), 241. 56. (a) Lichtenthaler, F. W. In Biorefineries – Industrial Processes and Products; Kamm, B., Gruber, P. R., Kamm, M., Eds.; Wiley–VCH, Weinheim, Germany, 2006; Vol. 2 (1), pp 3–59. (b) Delmas, M. Chem. Eng. Technol. 2008, 31, 792 57. Picataggio, S.; Beardslee, T. WO 2011/03034, 2011 (Verdezyne). 58. (a) Boussie, T.; Dias, E.; Fresco, Z.; et al. WO 2010/144862, 2010 (Rennovia). (b) Sims, B. Biorefining Mag. Dec 2010, 20. http://issuu.com/BBIInternational/docs/ dec10brm_digital. 59. Schlubach, H. H.; Lührs, E. Justus Liebigs Ann. Chem. 1941, 547 (1), 73. 60. Nishimura, T.; Nakatsubo, F. Cellulose 1997, 4, 109. 61. Karakawa, M.; Kamitakahara, H.; Takano, T.; Nakatsubo, F. Biomacromolecules 2002, 3, 538. 62. Gorius, O.; Bertho, J.-N.; Nizillard, J.-M. Anal. Chim. Acta 2001, 440 (2), 231. 63. Hill, K.; von Rybinski, W.; Stoll, G. Alkyl Polyglycosides – Technology, Properties and Applications; VCH: Weinheim, Germany, 1997. (a) Dewitt, R., Polymères bio sourcés – Normalisation et activités du Groupe SOLVAY, AG ValBiom (2010); http:// www.valbiom.be/files/gallery/presentationsolvayag2010ateliermpr1277457874.pdf (retrieved 15.09.2011). 64. Pang, K.; Kotek, R.; Tonelli, A. Prog. Polym. Sci. 2006, 31, 1009. 65. Amass, W.; Amass, A.; Tighe, B. Polym. Int. 1998, 47, 89. 66. Henton, D. E.; Gruber, P.; Lunt, J.; et al. In Natural Fibers, Biopolymers and Biocomposites; Mohanty, A. K., Misra, M., Drzal, L. T., Eds.; Taylor & Francis Books, Inc., 2005. 67. Jacobsen, S.; Fritz, H. G.; Degée, Ph.; et al. Polymer 2000, 41, 3395. 68. Anderson, K. S.; Schreck, K. M.; Hillmyer, M. A. Polym. Rev. 2008, 48, 85. 69. Gauthier, E.; Fuertes, P.; Cassagnau, P.; et al. J. Polym. Sci. A Polym. Chem. 2009, 47, 1440. 70. Shalaby, S. WO 2004/069918, 2004 (Polymed). 71. Bikiaris, D. N.; Achlias, D. S. Polymer 2008, 49, 3677. 72. (a) Tserki, V.; Matzinos, P.; Pavlidou, E.; et al. Polymer Degradation and Stability 2006, 91 (2), 367–376. (b) Carpenter, K. A.; Shalaby, W. S.; Anneaux, B. L. In Absorbable and Biodegradable Polymers; Shalaby, W. S., Burg, K. J. L., Eds.; CRC Press: Boca Raton, FL, 2004. 73. Fenouillot, F.; Rousseau, A.; Colomines, G.; et al. Prog. Polym. Sci. 2010, 35, 578. 74. Noordover, B. A. J.; van Staalduinen, V. G.; Duchateau, R.; et al. Biomacromolecules 2006, 7, 3406. 75. Doi, Y.; Kitamura, S.; Abe, H. Macromolecules 1995, 28, 4822. 76. Williams, S. F.; Martin, D. P.; Horowitz, D. M.; Peoples, O. P. Int. J. Biol. Macromol. 1999, 25 (1–3), 111. 77. Charbonneau, L.; Johnson, R. E.; Witeler, H. B.; Kanarian, G. U.S. Patent 6,063,464, 2000 (DuPont de Nemours). 78. Gandini, A.; Coelho, D.; Gomes, M.; et al. J. Mater. Chem. 2009, 19, 8656. 79. Gandini, A.; Belgacem, M. N. Prog. Polym. Sci. 1997, 22, 1203. 80. Gandini, A.; Silvestre, A. J. D.; Neto, C. P.; et al. J. Polym. Sci. A Polym. Chem. 2009, 47, 295. 81. (a) Kajiyama, T.; Taguchi, T.; Kobayashi, H.; et al. Polym. Degrad. Stab. 2003, 81 (3), 525. (b) Coulembier, O.; Degée, P.; Hedrick, J. L.; Dubois, P. Prog. Polym. Sci. 2006, 31 (8), 723.
81
82. Pascault, J.-P.; Sautereau, H.; Verdu, J.; Williams, R. J. J. Thermosetting
Polymers; Taylor & Francis Books, Inc., 2002.
83. Boufi, S.; Belgacem, M. N.; Quillerou, J.; Gandini, A. Macromolecules 1993,
26, 6706.
84. Spaans, C. J.; de Groot, J. H.; Dekens, F. G.; Pennings, A. J. U.S. Patent
6,784,273, 1999 (Polyganics).
85. Chang, W. L. U.S. Patent 6,420,446, 2002 (Witco). 86. Frost, J. W. U.S. Patent 2,009,005,532, 2009 (Michigan State University). 87. Schwamborn, M. Polym. Degrad. Stab. 1998, 59, 39. 88. Rohwerder, T. World Congress on Industrial Biotechnology & Bioprocessing,
Washington, DC, 2010, June 27–30.
89. Nishida, H.; Andou, Y.; Watanabe, K.; et al. Macromolecules 2011, 44, 12. 90. Fukuhara, D.; Sundberg, D. J. Coat. Technol. Res. 2005, 2, 509. 91. Fukuoka, S.; Tojo, M.; Hachiya, H.; et al. Polym. J. 2007, 39, 91. 92. Masubuchi, T.; Ueno, E.; Yoshioka, Y.; Tsukimori, Y. WO 088152, 2006 (Asahi Chem. Corp.). 93. Matsuo, J.; Aoki, K.; Sanda, F.; Endo, T. Macromolecules 1998, 31, 4432. 94. Luinstra, G. A. Polym. Rev. 2008, 48 (1), 192. 95. (a) Kuran, W.; Sobczak, M.; Listos, T.; et al. Polymer 2000, 41, 8531. (b) Bisht, K. S.; Svirkin, Y. Y.; Henderson, L. H.; et al. Macromolecules 1997, 30, 7735. 96. (a) Akimichi, O.; Takanori, M. JP Patent 084532 (A), 2009 (Teijin LTD). (b) Noordoven, B.; Duchateau, R.; Koning, C.; et al. WO 2009/033934 A1, 2009 (Dutch Polymer Institute, DPI). 97. Fuji, M.; Akita, M.; Tanaka, T., EP 2 033 981 A1, 2009 (Mitsubishi Chem.).
http://www.japanchemicalweb.jp/ (accessed July 20, 2009).
98. (a) Jansen, B. J. P.; Kamps, J.H.; Looij, H.; Kung, E. WO 2009/052463 A1, 2009 (Sabic). (b) Kinoshita, M.; Saito, M.; Hironaka, K. EP 2149 589 A1, 2010 (Teijin LTD). 99. Gidron, O.; Dadvand, A.; Sheynin, Y.; et al. Chem. Commun. 2011, 47, 1976. 100. Szkudlarek, M. H.; Jansen, J. F. G. A.; Duyvestijn, S. J. WO 2010/108968 A1, 2010 (DSM). 101. Anders, R. M.; Anders, K. R.; Becker, D. K. WO 99/23122, 1998 (Composite Technology Group LLC). (b) Szkudlarek, M. H.; Jansen, J. F. G. A. WO 2010/ 108939 A1, 2010 (DSM). (c) Szkudlarek, M. H.; Jansen, J. F. G. A.; Bleeker, L. J. WO 2010/108941 A1, 2010 (DSM). 102. Gandini, A. In Epoxy Polymers: New Materials and Innovations; Pascault, J.-P., Williams, R. J. J., Eds.; Wiley, 2010; Vol. 55. 103. (a) Takada, Y.; Shinbo, K.; Someya, Y.; et al. J. Appl. Polym. Sci. 2009, 113, 479. (b) Shibata, M.; Nakai, K. J. Polym. Sci. B Polym. Phys. 2010, 48, 425. (c) Stewart, D. Industrial Crops and Products, 2008, 27, 202. (d) El Mansouri, N-E., Yuan, Q., Huang, F., BioResources, 2011, 6, 2492. 104. (a) Feng, X.; East, A. J.; Hammonda, W. B.; et al. Polym. Adv. Technol. 2011, 22, 139. (b) Chrysanthos, M., Galy, J., Pascault, J. P., Polymer, 2011, 52, 3611. 105. Kim, Y. H.; An, E. S.; Park, S. Y.; et al. J. Molecular Catalysis B: Enzymatic 2007, 45, 39. 106. Fitzpatrick, S. W. U.S. Patent 5,608,105, 1995 (Biofine). 107. Nouailhas, H.; Aouf, C.; Le Guerneve, C.; et al. J. Polym. Sci. Part A: Polymer Chemistry, 2011, 49, 2261. 108. (a) Pfeffer, J.; Ortelt, M.; Spyrou, E.; et al. WO 2011/000585 A1, 2011. (b) Pfeffer, J.; Ortelt, M.; Spyrou, E.; et al. WO 2011/000586 A1, 2011. (c) Spyrou, E.; Pfeffer, J.; Loesch, H.; et al. WO 2011/000587 A1, 2011 (Evonik Degussa GmbH). 109. Lindberg, P.; Park, S.; Melis, A. Metab. Eng. 2010, 12, 70–79. 110. Haas, T.; Kircher, K.; Köhler, T.; et al. In Sustainable Solutions for Modern Economies; Höfer, R., Ed.; RSC Publication: Cambridge, UK, 2009, pp 436–478.
82
Carbohydrate-Based Polymer Building Blocks & Biopolymers | Mono-, Di-, and Oligosaccharides
Biographical Sketches Professor Jean-Pierre Pascault has been emeritus at INSA (National Institute of Applied Science), Lyon, France since October 2006. He was professor in the same Institute from 1983 to October 2005; director of the Laboratory of Macromolecular Materials (associated with CNRS) from 1982 to 1998; director of a CNRS Polymer Network Group (FR CNRS) from 2000 to 2006; president of the French Polymer Group (GFP) and of the Polymer Division of the French Chemical Society (SCF) from 2001 to 2004. He has authored more than 300 scientific publications including several book chapters, two books (Thermosetting Polymers (2002) and Epoxy Polymers. New Materials and Innovations (2010)) and more than 30 patents. The key focuses of his research activities are the following: polymer chemistry; (nanostructured) polymer network formation; polyepoxies; polyurethanes; polyacrylates; UV curing; polymer blends; composites; coatings; including bio-based polymers.
Rainer Höfer graduated in inorganic chemistry with Professor Oskar Glemser at the Georg-August Universität zu Göttingen in 1973 with work on sulfur–nitrogen–fluorine chemistry. He spent 3 years at the Technical University of Oran (ENSEP), Algeria, as Maître de Conférences and Directeur de l’Institut de Chimie before joining Henkel in Düsseldorf. With Henkel KGaA and then as vice president of Research & Technology with Cognis GmbH in Monheim, he has assumed global research and development, application technology, technical sales service, strategic business development, and technology scouting responsibilities in oleochemistry, polymer chemistry, and surfactant chemistry for the polymerization, coatings, graphic arts, adhesives, engineering plastics, agrochemical, synthetic lubricants, mining, and pulp and paper markets. He is a founder of Editorial Ecosiris with consultancy and publishing activities in the domains of green chemistry, renewable resources, sustainable development, and interculturation.
Patrick Fuertes graduated in chemical engineering at the University of Marseille (ENSCL) in 1978. Then, he moved to Canada at the University of Quebec (Trois-Rivières) where he had his first experience in the field of cellulose chemistry. At the end of 1981, he joined Roquette, at the R & D Center in Lestrem, northern France. He started in the laboratory of sugar chemistry and was in charge of the Chemistry Department in 1986 with the aim to develop new products and new processes related to starch and sugar chemistry. In 2006, Patrick Fuertes took the responsibility of the Research Division for the coordination of the research programs involving the chemistry, microbiology, fermentation, and biochemistry depart ments. During this period, he worked out the scientific outline of the BioHub® program supported by OSEO Innovation. He was appointed director of the BioHub program in 2009. The object of the BioHub® programme is to develop with industrial and scientific partners new production outlets for chemicals based on renewable agricultural raw materials such as grain.