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Masterbatches add functionality to PLA
APPLICATIONS
News
Masterbatches add functionality to PLA Clariant Masterbatches has introduced new functional additive masterbatches to its CESA®-natur product range. The biodegradable masterbatches made from renewable resources are claimed to be ideal for use with biopolymers such as polylactic acid (PLA). The natural masterbatches can also be formulated for use in conventional polymers as alternatives to non-renewable additives. According to the company, the new masterbatches – including slip/antiblock agents, UV/light stabilizers, antioxidants and antistatic agents – feature not only a biopolymer carrier resin, but also naturally occurring substances that are completely renewable, biodegradable and, in most cases, compostable. These products have successfully passed strict screening procedures and are available for immediate use. Clariant Masterbatches is continuing research to expand the range of CESA-natur additive masterbatches. Development and testing is currently under way on natural impact modifiers and metal deactivators for PLA. Clariant Masterbatches adds that CESA-natur slip additive masterbatches perform well in PLA film applications. This newly developed system is based on pure, naturally occurring waxes that give very good slip properties. The coefficient of friction (CoF)
in PLA films obtained by using CESA-natur slip additive is close to the values achieved with modern synthetic waxes, which are based on petrochemicals. The use of CESA-natur slip appears to have only a marginal influence on transparency. CESA-natur light masterbatches provide light stabilization in both conventional and biopolymers. They can also function as a UV filter to protect the contents of packaging made of bioplastics such as PLA. Like synthetic additives, they are based on aromatic molecules, but the CESAnatur UV masterbatches use naturally occurring ingredients. Carrier resins can include any of the common biopolymers. Processing characteristics are similar to those associated with conventional masterbatches. Strict product safety regulations and screening apply, despite the natural origin of the materials. In the past, the company says that the natural compounds chosen for UV protection have been coloured and usually show low thermal stability at processing temperatures above 200°C. The newest CESA-natur light masterbatches, however, are formulated from light-coloured substances that are substantially more heat stable and offer UV protection comparable to conventional synthetic UV absorbers.
Other CESA-natur masterbatches currently available include CESAnatur antioxidants, which use natural antioxidants like vitamin E, and CESA-natur antistatic masterbatches, which take advantage of some of the same additives that are commonly used in food products. In addition to the CESA-natur additive masterbatches, which can be used in biopolymers or conventional resins, Clariant Masterbatches adds that it has developed two other masterbatches – CESA-extend and HYDROCEROL® – that significantly improve the processing and end-use performance of PLA. One factor that has been limiting the acceptance of PLA is its processing instability. It is highly vulnerable to thermal, oxidative and hydrolytic degradation, all of which may occur during processing. The result of these degenerative effects is polymer chain cleavage that, in turn, results in loss of molecular weight and deterioration of rheological properties. CESA-extend, a masterbatch based on a molecule originally developed to re-link polymer chains in degraded condensation polymers like recycled PET, has more recently been showing great promise in processing PLA and other biopolymers, including PHA (polyhydroxyalkanoate)
and PHB (polyhydroxybutyrate). Clariant has demonstrated that CESA-extend can significantly improve the melt strength of PLA, allowing for more reliable sheet extrusion and superior bubble formation and stability in blownfilm processing. PLA is also finding application in foamed products like grocery-store meat trays, where the biopolymer replaces styrene. HYDROCEROL chemical foaming agent (CFA) masterbatches are being used in PLA foam extrusion and increasingly as a nucleating agent in direct-gas foaming to produce the uniform, finecelled structure that end-users demand. Adding CESA-extend to the foam, in combination with HYDROCEROL, has been shown to enhance molecular weight and melt-strength characteristics resulting in a more easily controllable process. Both these additives are artificially derived, and so they do not fit the definition of a natural and renewable feedstock, says the company. However, they do make it possible to use renewable biopolymers more readily so the environmental benefits outweigh any negative effect. Contact: Clariant Masterbatches Website: www.clariant. masterbatches.com
New peroxide concentrates offer improved performance Polyvel, Inc. has developed a line of free flowing pelletized peroxide concentrates specifically for use in crosslinking polyethylene. The PCL series is claimed to be easier and safer to use than alkyl peroxide powders and liquids. It also eliminates ‘bridging’ - often seen when using powders, creating
more accurate dosing, which leads to more consistent properties. When these concentrates are let down into polyethylene, through extrusion, injection moulding, blow moulding, or rotational moulding, the plastic exhibits greater melt strength, while the final part exhibits greater
Plastics Additives & Compounding September/October 2008
mechanical properties such as tensile, flexural and impact strength. The company adds that if desired, part thickness and weight can be decreased, while existing properties are maintained. Longer shelf life is another advantage of peroxide concentrates, as they
20
retain their properties longer than liquids and powders. Polyvel says it can offer several different peroxide chemistries, with loadings from 1-40 per cent, on carrier systems that are compatible with different applications. Contact: Polyvel Inc. Website: www.polyvel.com
News
Masterbatches add functionality to PLA Clariant Masterbatches has introduced new functional additive masterbatches to its CESA®-natur product range. The biodegradable masterbatches made from renewable resources are claimed to be ideal for use with biopolymers such as polylactic acid (PLA). The natural masterbatches can also be formulated for use in conventional polymers as alternatives to non-renewable additives. According to the company, the new masterbatches – including slip/antiblock agents, UV/light stabilizers, antioxidants and antistatic agents – feature not only a biopolymer carrier resin, but also naturally occurring substances that are completely renewable, biodegradable and, in most cases, compostable. These products have successfully passed strict screening procedures and are available for immediate use. Clariant Masterbatches is continuing research to expand the range of CESA-natur additive masterbatches. Development and testing is currently under way on natural impact modifiers and metal deactivators for PLA. Clariant Masterbatches adds that CESA-natur slip additive masterbatches perform well in PLA film applications. This newly developed system is based on pure, naturally occurring waxes that give very good slip properties. The coefficient of friction (CoF)
in PLA films obtained by using CESA-natur slip additive is close to the values achieved with modern synthetic waxes, which are based on petrochemicals. The use of CESA-natur slip appears to have only a marginal influence on transparency. CESA-natur light masterbatches provide light stabilization in both conventional and biopolymers. They can also function as a UV filter to protect the contents of packaging made of bioplastics such as PLA. Like synthetic additives, they are based on aromatic molecules, but the CESAnatur UV masterbatches use naturally occurring ingredients. Carrier resins can include any of the common biopolymers. Processing characteristics are similar to those associated with conventional masterbatches. Strict product safety regulations and screening apply, despite the natural origin of the materials. In the past, the company says that the natural compounds chosen for UV protection have been coloured and usually show low thermal stability at processing temperatures above 200°C. The newest CESA-natur light masterbatches, however, are formulated from light-coloured substances that are substantially more heat stable and offer UV protection comparable to conventional synthetic UV absorbers.
Other CESA-natur masterbatches currently available include CESAnatur antioxidants, which use natural antioxidants like vitamin E, and CESA-natur antistatic masterbatches, which take advantage of some of the same additives that are commonly used in food products. In addition to the CESA-natur additive masterbatches, which can be used in biopolymers or conventional resins, Clariant Masterbatches adds that it has developed two other masterbatches – CESA-extend and HYDROCEROL® – that significantly improve the processing and end-use performance of PLA. One factor that has been limiting the acceptance of PLA is its processing instability. It is highly vulnerable to thermal, oxidative and hydrolytic degradation, all of which may occur during processing. The result of these degenerative effects is polymer chain cleavage that, in turn, results in loss of molecular weight and deterioration of rheological properties. CESA-extend, a masterbatch based on a molecule originally developed to re-link polymer chains in degraded condensation polymers like recycled PET, has more recently been showing great promise in processing PLA and other biopolymers, including PHA (polyhydroxyalkanoate)
and PHB (polyhydroxybutyrate). Clariant has demonstrated that CESA-extend can significantly improve the melt strength of PLA, allowing for more reliable sheet extrusion and superior bubble formation and stability in blownfilm processing. PLA is also finding application in foamed products like grocery-store meat trays, where the biopolymer replaces styrene. HYDROCEROL chemical foaming agent (CFA) masterbatches are being used in PLA foam extrusion and increasingly as a nucleating agent in direct-gas foaming to produce the uniform, finecelled structure that end-users demand. Adding CESA-extend to the foam, in combination with HYDROCEROL, has been shown to enhance molecular weight and melt-strength characteristics resulting in a more easily controllable process. Both these additives are artificially derived, and so they do not fit the definition of a natural and renewable feedstock, says the company. However, they do make it possible to use renewable biopolymers more readily so the environmental benefits outweigh any negative effect. Contact: Clariant Masterbatches Website: www.clariant. masterbatches.com
New peroxide concentrates offer improved performance Polyvel, Inc. has developed a line of free flowing pelletized peroxide concentrates specifically for use in crosslinking polyethylene. The PCL series is claimed to be easier and safer to use than alkyl peroxide powders and liquids. It also eliminates ‘bridging’ - often seen when using powders, creating
more accurate dosing, which leads to more consistent properties. When these concentrates are let down into polyethylene, through extrusion, injection moulding, blow moulding, or rotational moulding, the plastic exhibits greater melt strength, while the final part exhibits greater
Plastics Additives & Compounding September/October 2008
mechanical properties such as tensile, flexural and impact strength. The company adds that if desired, part thickness and weight can be decreased, while existing properties are maintained. Longer shelf life is another advantage of peroxide concentrates, as they
20
retain their properties longer than liquids and powders. Polyvel says it can offer several different peroxide chemistries, with loadings from 1-40 per cent, on carrier systems that are compatible with different applications. Contact: Polyvel Inc. Website: www.polyvel.com