- Email: [email protected]
Production and Application of Advanced Composite Materials in Rail Cars Development: Prospect in South African Industry
Available online at www.sciencedirect.com
Available online at www.sciencedirect.com Available online at www.sciencedirect.com
ScienceDirect Procedia Manufacturing (2018) 000–000 Procedia Manufacturing 35 00 (2019) 471–476 Procedia Manufacturing 00 (2018) 000–000
www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia
2nd 2nd International International Conference Conference on on Sustainable Sustainable Materials Materials Processing Processing and and Manufacturing Manufacturing (SMPM 2019) (SMPM 2019)
Production Production and and Application Application of of Advanced Advanced Composite Composite Materials Materials in in Rail Rail Cars Cars Development: Development: Prospect Prospect in in South South African African Industry Industry a,∗ a b c d a a ID ID Ibrahim Ibrahima,∗,, T T Jamiru Jamirua,, ER ER Sadiku Sadikub,, WK WK Kupolati Kupolatic,, K K Mpofu Mpofud,, AA AA Eze Ezea,, CA CA Uwa Uwaa
aDepartment of Mechanical Engineering Tshwane University of Technology Pretoria, 0183, South Africa aDepartment of Mechanical Engineering Tshwane University of Technology Pretoria, 0183, South Africa for NanoEngineering Department Metallurgy for NanoEngineering Research Research (INER) (INER) and and Department of of Chemical ChemicalSouth Metallurgy and and Materials Materials Engineering, Engineering, Tshwane Tshwane University University of of Technology, Technology, Pretoria, Pretoria, 0183 0183 South Africa Africa cInstitute for NanoEngineering Research (INER) and Department of Civil Engineering Tshwane University of Technology Pretoria, 0183, South cInstitute for NanoEngineering Research (INER) and Department of Civil Engineering Tshwane University of Technology Pretoria, 0183, South Africa Africa dDepartment of Industrial Engineering Tshwane University of Technology, Pretoria, 0183, South Africa dDepartment of Industrial Engineering Tshwane University of Technology, Pretoria, 0183, South Africa bInstitute bInstitute
Abstract Abstract The The business business hub hub of of any any society society in in the the developed developed and/or and/or developing developing nations nations are are characterized characterized by by constantly constantly growing growing population, population, which which is is aa result result of of industrialization industrialization and and urbanization. urbanization. This This growth growth often often necessitates necessitates infrastructural infrastructural development development (better, (better, safer, safer, faster faster and and cheaper cheaper means means of of transportation transportation of of goods goods and and services), services), high high energy energy demand demand and and environmental environmental decay decay (high (high emission emission of into the the atmosphere atmosphere leading leading global global warming). warming). In In order order to to resolve resolve the the problems, problems, there there is is aa need need to to develop develop of carbon carbon dioxide dioxide (CO (CO22 )) into improved improved lightweight lightweight polymeric polymeric composite composite materials, materials, which which can can be be used used in in the the construction construction and and transportation transportation industries. industries. The The research reinforced recycled polypropylene (PP) nanocomposites. The fiber was treated with research focused focused on on developing developing natural natural fiber fiber reinforced recycled polypropylene (PP) nanocomposites. The fiber was treated with o 5% 5% alkaline alkaline solution solution for for 2 2 hours hours at at 60 60 o C C in in aa vacuum vacuum oven. oven. The The fiber fiber (10, (10, 20, 20, 30 30 and and 40 40 %wt), %wt), nanoclay nanoclay (1, (1, 3, 3, 5 5 %wt) %wt) and and compatibilizer were were melt melt blend blend with with the the recycled recycled PP. PP. Based Based on on the the results, results, it it was was observed observed that that fiber fiber treatment, treatment, increasing increasing fiber fiber compatibilizer contents contents and and nanoparticles nanoparticles increased increased the the overall overall strength strength and and thermal thermal stability stability of of the the prepared prepared composites. composites. The The rate rate of of moisture moisture absorption was equally enhanced. The material developed can be used to produce seats and backrest for passage train absorption was equally enhanced. The material developed can be used to produce seats and backrest for passage train and and other other interior interior part part of of the the passenger passenger train. train. cc 2018 The Authors. Published by Elsevier B. 2018 The The Authors. Authors. Published Published by by Elsevier Elsevier B.V. B. V. V. © 2019 Peer-review under responsibility of theorganizing committee of SMPM 2019. Peer-review under responsibility of theorganizing Peer-review under responsibility of the organizingcommittee committeeofofSMPM SMPM2019. 2019. Composite; Nanoparticle; Natural fiber; Transportation Keywords: Keywords: Composite; Nanoparticle; Natural fiber; Transportation
1. 1. Introduction Introduction The The constant constant increase increase in in population population has has led led to to the the observed observed increase increase in in basic basic requirement requirement for for the the masses masses in in most most developed and developing countries. The demand has a direct impact on the infrastructural need. One of the developed and developing countries. The demand has a direct impact on the infrastructural need. One of the several several infrastructural infrastructural needs needs is is the the mode mode of of transportation. transportation. In In the the case case of of Africa, Africa, road road transportation transportation is is the the most most commonly commonly used means of transportation. The increasing population demand for alternative means of movement, used means of transportation. The increasing population demand for alternative means of movement, which which has has the the ∗ ∗
Corresponding Corresponding author. author. Tel.: Tel.: +27-74-252-6568 +27-74-252-6568 E-mail address: [email protected] E-mail address: [email protected]
2351-9789 2018 The The Authors. Authors. Published Published by by Elsevier Elsevier B. B. V. V. cc 2018 2351-9789 Peer-review under under responsibility of of theorganizing committee committee of of SMPM SMPM 2019. 2019. Peer-review 2351-9789 © 2019responsibility The Authors. theorganizing Published by Elsevier B.V. Peer-review under responsibility of the organizing committee of SMPM 2019. 10.1016/j.promfg.2019.05.069
472 2
I.D. Ibrahim et al. / Procedia Manufacturing 35 (2019) 471–476 I.D. Ibrahim et al / Procedia Manufacturing 00 (2018) 000–000
potentials to reduce road congestion, reduce the high volume of road crashes (which in some cases results to fatalities) and the extension in the lifespan of the road. South Africa as a country had their first and second train in the year 1860 (Durban) and 1862 (Cape Town) respectively [1]; electrification of rail was achieved in the 1920s. Since then, several improvements have been made to increase the performance, comfort and reduce the weight of the passenger train. The weight of the rail cars has a direct impact on the wearing rate of the rail tracks, the speed of the train and total carbon dioxide (CO2 ) emission. Therefore, arise the need to finding alternative materials that can be used to replace some of the interior components of the passenger trains. The alternative material should be sustainable having enhanced properties and that is where advance composite materials comes into the material mix. Advance composites materials have improved properties such high strength-to-weight, improve thermal performance, cost effective and moisture absorption rate [2]. 2. Materials and Method 2.1. Materials and Preparation The Council for Scientific and Industrial Research (CSIR) in Port Elisabeth, South Africa donated the sisal fiber and recycled polypropylene that was used for the research work. Improvement of the the sisal fiber strength was achieved by treating with 5% sodium hydroxide solution. The treatment was performed in a vacuum oven maintaining the temperature at 70 o C for 2 hours. The fiber was rinsed with water, 1% acetic acid solution and distilled water in that order to remove excess alkali. The treatment process and test samples are shown in Fig. 1. The treated fiber was left to dry for 24 hours at room temperature and was finally placed in a vacuum oven for 24 hours at a temperature of 60 o C. Cutting of the fiber was done to a length of approximately 5 mm. Organically modified montmorillonites (Cloisite30B) was supplied by Southern Clay Products Inc., USA, while Maleic anhydride grafted polypropylene (MAPP, FusabondP MZ 109D, DuPont) was supplied by Chemical Innovation Co., Ltd. Both materials were placed in the vacuum oven for 4 hours at 60 o C to remove moisture. 2.2. Method The melt blend approach was used. The premixing was done using HAAKE PolyLab OS Rheomix batch mixer (Thermo Electron Co., USA) with the following parameters: temperature of 200 o C, rotor speed of 60 rpm, for 8 minutes. The premixed polypropylene and MAPP were poured first into the Rheomix mixer, followed by the nanoclay and then sisal fiber. The MAPP was maintained at 5 %wt based on literature [3] while the nanoclay (1, 3 and 5 %wt) and fiber (10, 20, 30 and 40 %wt) were varied. The control sample was also prepared. The premixed samples were press moulded with the following parameters: temperature of 200 o C, pressure of 1500 psi and processing time of 8 minutes using Carver Laboratory Press. 3. Characterization 3.1. Mechanical Properties The mechanical properties (tensile strength and tensile modulus) were conducted using an Instron 5966 tester (Instron Engineering Corporation, USA) with a cross load cell of 10 kN, at a single strain rate of 5 mm/min according to ASTM D638. The presented results are average of five various tests. The impact testing was conducted using an Impactometer (Ceast, Italy) in line with ASTM D256 with a notch angle of 45o and depth of 2.5 mm. 3.2. Thermal Analyses The composites thermal behaviours were verified using a thermogravimetric analyser (TGA; TA Instrument, Model Q500, USA). Approximately 5 mg weight per sample was used. Heating rate was maintained at 10 o C/min starting from room temperature to 700 o C under air flow.
I.D. Ibrahim et al. / Procedia Manufacturing 35 (2019) 471–476 I.D. Ibrahim et al / Procedia Manufacturing 00 (2018) 000–000
473 3
Fig. 1. Fiber treatment (a) and (b), composites compounding (c), impact test samples (d) and tensile test samples (e)
3.3. Moisture Absorption The moisture absorption was studied by immersing the composite samples in water. The initial weights before and after immersing in water were measured. The percentage change in weight was determined using Equation 1. W=
(m f − mi ) × 100 mi
(1)
Where mi and m f are the initial weight before and after immersion in water respectively, W is the percentage water absorption. 4. Results and Discussion 4.1. Mechanical Properties Fig. 2 shows the tensile strength and modulus of the control sample and the reinforced polypropylene composites. From the figure it is observed that generally, fiber surface modification, incorporation of MAPP and nanoclay into polypropylene matrix showed noticeable improvement in the tensile strength and tensile modulus of all prepared composites. Little improvement was observed with the fiber treatment while further improvement was observed with the inclusion of 1 %wt nanoclay for tensile strength and tensile modulus compared to untreated sisal fiber reinforced composites. Similar observation was made by Chanprapanon et al. [4] for 1 %wt nanoclay inclusion with respect to
474 4
I.D. Ibrahim et al. / Procedia Manufacturing 35 (2019) 471–476 I.D. Ibrahim et al / Procedia Manufacturing 00 (2018) 000–000
Fig. 2. Tensile strength (a) and tensile modulus (b) of sisal fiber reinforced composites
Fig. 3. Impact strength of sisal fiber reinforced composites
tensile strength and tensile modulus of reinforced composites. Additional increase in nanoclay content led to further improvement in tensile strength and modulus, which was also reported by Lee et al. [5]. The improvement is due to proper nanoclay dispersion in the polymer matrix and fiber. Optimal tensile strength and modulus of 55.95(1.58) MPa and 1.7(0.17) GPa respectively was recorded based on the prepared samples when 5 %wt nanoclay was incorporated. Impact strength for the prepared samples are shown in Fig. 3. Fiber treatment led to an increase in impact strength compared with control sample. Incorporation of 1 %wt clay showed a reduction which is a result inadequate dispersion of the clay in the matrix. The impact strength showed much improvement of approximately 8.76(0.64) KJ/m2 with the incorporation of 5 %wt nanoclay.
I.D. Ibrahim et al. / Procedia Manufacturing 35 (2019) 471–476 I.D. Ibrahim et al / Procedia Manufacturing 00 (2018) 000–000
475 5
4.2. Thermal Analyses The thermal stability was observed to be lower with the composites containing treated fiber and MAPP when compared to the untreated sisal fiber reinforced polypropylene composites. This may be due to the presence of hemicellulose and lignin. The nanoclay inclusion further improved the thermal stability as shown in Table 1 which has been widely reported in literature, the inclusion of inorganic fillers into polymer matrix helped to improve thermal stability by absorbing and dissipating the heat energy entering the material [6][7][8]. Further increase was observed with additional increase in nanoclay contents. Table 1. Thermal properties of 40 %wt sisal fiber reinforced polypropylene composites Samples
T 5% (o C)
T 10% (o C)
T Max (o C)
Residue at 500o C
Control UT40/PP T40/PP T40/MAPP/PP T40/MAPP/C1/PP T40/MAPP/C3/PP T40/MAPP/C5/PP
301.88 274.45 271.30 262.64 262.80 265.76 282.11
323.01 293.70 294.69 281.83 285.75 288.27 306.87
379.79 370.90 351.97 350.39 351.89 352.54 394.14
4.044 3,413 3.327 2.943 4.748 8.919 16.83
UT: Untreated fiber, T: Treated fiber, C1: 1%wt clay, C3: 3%wt clay, C5: 5%wt clay T 5% : Temperature at 5% weight loss, T 10% : Temperature at 10% weight loss, T Max : Temperature at maximum decomposition.
4.3. Moisture Absorption The influence of treating the fiber, inclusion of compatibilizer on sisal reinforced composites is shown in Fig. 4. From the result, it was observed that very little water was absorbed by the control sample for the period of immersion, this is due to the hydrophobic nature plastic materials. The composite samples containing fibers were observed to absorb higher water, this was due to natural fibers hydrophilic nature. The fiber surface modification, filler inclusion and compatibilizer reduced the rate of water absorption of the fiber reinforced composites. Similar observation was reported by Mohan and Kanny [9]. The fiber surface treatment removed the presence of lignin, hemicellulose, wax and dirt which were responsible for the high level of water intake from the fiber-based polymer composites [10]. The inclusion of MAPP enhanced the adhesion between the matrix, filler and fiber due to good interfacial reaction that was created. 4.4. Conclusion The study presented the effect of fiber surface treatment, use of MAPP and incorporation of nanoclay to enhance the mechanical properties of reinforce polymeric composites applicable for the interior components of passenger trains. Conclusion from the study are presented as follows: • There was an improvement in the mechanical properties of composites treated with alkali solution. • MAPP and nanoclay inclusion further improved mechanical properties of sisal fiber reinforced composites. • Increase in fiber content led to increase in tensile strength, tensile modulus and impact strength of reinforced polypropylene composites. • Composite containing 5 %wt MAPP, 5 %wt nanoclay and 40 %wt treated fibers, showed the optimum mechanical properties based on the samples that were developed. • Thermal stability was observed to reduced when sisal fiber was introduced into the polymer. MAPP and nanoclay inclusion led to improvement in the thermal stability. • Significant decrease in water absorption was observed for composites containing treated fiber and nanoclay nanoparticle compared with the untreated fiber reinforced composites. Furthermore, increasing immersion time in water led to increase in water uptake fiber based composites.
I.D. Ibrahim et al. / Procedia Manufacturing 35000–000 (2019) 471–476 I.D. Ibrahim et al / Procedia Manufacturing 00 (2018)
476 6
Fig. 4. Water absorption rate of fiber reinforced composites
Acknowledgements Authors would like to thank the Tshwane University of Technology Pretoria, South Africa for providing a conducive environment to carry out this research work. Also wish to acknowledge the financial support from the CSIRDST Inter-Programme, South Africa, towards the research. The authors equally appreciate the financial support from Gibela, South Africa. References [1] [2] [3] [4] [5] [6] [7] [8] [9] [10]
M. Mitchell, Civil Engine. 2017 (2017) 68–70. I.D. Ibrahim, T. Jamiru, E.R. Sadiku, W.K. Kupolati, S.C. Agwuncha. J. Nanotechnol. (2016) http://dx.doi.org/10.1155/2016/4235975. N. Hamour, A. Boukerrou, A. Bourmaud, H. Djidjelli, Y. Grohens. Cellul. Chem. Technol. 50 (2016) 1069–1076 W. Chanprapanon, N. Suppakarn, K. Jarukumjorn. In Proceedings of the 18th International Conference on Composite Materials (ICCM11). August 2011. Y.H. Lee, T. Kuboki, C.B. Park, M. Sain, M. Kontopoulou. J. Appl. Polym. Sci. 118 (2010) pp.452–461. H. Alamri, I.M, Low, Z. Alothman. Composites: Part B. 43 (2012) 2762–2771. S.Y. Lee, I.A. Kang, G.H. Doh, W.J. Kim, J.S. Kim, H.G. Yoon and Q. Wu. eXPRESS Polym. Let. 2 (2008) 78–87. N.R. Paluvai, S. Mohanty, S.K. Nayak. J. Appl. Polym. Sci. 2015. DOI: 10.1002/APP.42068. T.P. Mohan, K. Kanny. Comp. Part A: Appl. Sci. Manuf. 43 (2012) 1989–1998. S. Kaewkuk, W. Sutapun, K. Jarukumjorn. Composites Part B: Engine. 45 (2013) 544–549.
Available online at www.sciencedirect.com Available online at www.sciencedirect.com
ScienceDirect Procedia Manufacturing (2018) 000–000 Procedia Manufacturing 35 00 (2019) 471–476 Procedia Manufacturing 00 (2018) 000–000
www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia
2nd 2nd International International Conference Conference on on Sustainable Sustainable Materials Materials Processing Processing and and Manufacturing Manufacturing (SMPM 2019) (SMPM 2019)
Production Production and and Application Application of of Advanced Advanced Composite Composite Materials Materials in in Rail Rail Cars Cars Development: Development: Prospect Prospect in in South South African African Industry Industry a,∗ a b c d a a ID ID Ibrahim Ibrahima,∗,, T T Jamiru Jamirua,, ER ER Sadiku Sadikub,, WK WK Kupolati Kupolatic,, K K Mpofu Mpofud,, AA AA Eze Ezea,, CA CA Uwa Uwaa
aDepartment of Mechanical Engineering Tshwane University of Technology Pretoria, 0183, South Africa aDepartment of Mechanical Engineering Tshwane University of Technology Pretoria, 0183, South Africa for NanoEngineering Department Metallurgy for NanoEngineering Research Research (INER) (INER) and and Department of of Chemical ChemicalSouth Metallurgy and and Materials Materials Engineering, Engineering, Tshwane Tshwane University University of of Technology, Technology, Pretoria, Pretoria, 0183 0183 South Africa Africa cInstitute for NanoEngineering Research (INER) and Department of Civil Engineering Tshwane University of Technology Pretoria, 0183, South cInstitute for NanoEngineering Research (INER) and Department of Civil Engineering Tshwane University of Technology Pretoria, 0183, South Africa Africa dDepartment of Industrial Engineering Tshwane University of Technology, Pretoria, 0183, South Africa dDepartment of Industrial Engineering Tshwane University of Technology, Pretoria, 0183, South Africa bInstitute bInstitute
Abstract Abstract The The business business hub hub of of any any society society in in the the developed developed and/or and/or developing developing nations nations are are characterized characterized by by constantly constantly growing growing population, population, which which is is aa result result of of industrialization industrialization and and urbanization. urbanization. This This growth growth often often necessitates necessitates infrastructural infrastructural development development (better, (better, safer, safer, faster faster and and cheaper cheaper means means of of transportation transportation of of goods goods and and services), services), high high energy energy demand demand and and environmental environmental decay decay (high (high emission emission of into the the atmosphere atmosphere leading leading global global warming). warming). In In order order to to resolve resolve the the problems, problems, there there is is aa need need to to develop develop of carbon carbon dioxide dioxide (CO (CO22 )) into improved improved lightweight lightweight polymeric polymeric composite composite materials, materials, which which can can be be used used in in the the construction construction and and transportation transportation industries. industries. The The research reinforced recycled polypropylene (PP) nanocomposites. The fiber was treated with research focused focused on on developing developing natural natural fiber fiber reinforced recycled polypropylene (PP) nanocomposites. The fiber was treated with o 5% 5% alkaline alkaline solution solution for for 2 2 hours hours at at 60 60 o C C in in aa vacuum vacuum oven. oven. The The fiber fiber (10, (10, 20, 20, 30 30 and and 40 40 %wt), %wt), nanoclay nanoclay (1, (1, 3, 3, 5 5 %wt) %wt) and and compatibilizer were were melt melt blend blend with with the the recycled recycled PP. PP. Based Based on on the the results, results, it it was was observed observed that that fiber fiber treatment, treatment, increasing increasing fiber fiber compatibilizer contents contents and and nanoparticles nanoparticles increased increased the the overall overall strength strength and and thermal thermal stability stability of of the the prepared prepared composites. composites. The The rate rate of of moisture moisture absorption was equally enhanced. The material developed can be used to produce seats and backrest for passage train absorption was equally enhanced. The material developed can be used to produce seats and backrest for passage train and and other other interior interior part part of of the the passenger passenger train. train. cc 2018 The Authors. Published by Elsevier B. 2018 The The Authors. Authors. Published Published by by Elsevier Elsevier B.V. B. V. V. © 2019 Peer-review under responsibility of theorganizing committee of SMPM 2019. Peer-review under responsibility of theorganizing Peer-review under responsibility of the organizingcommittee committeeofofSMPM SMPM2019. 2019. Composite; Nanoparticle; Natural fiber; Transportation Keywords: Keywords: Composite; Nanoparticle; Natural fiber; Transportation
1. 1. Introduction Introduction The The constant constant increase increase in in population population has has led led to to the the observed observed increase increase in in basic basic requirement requirement for for the the masses masses in in most most developed and developing countries. The demand has a direct impact on the infrastructural need. One of the developed and developing countries. The demand has a direct impact on the infrastructural need. One of the several several infrastructural infrastructural needs needs is is the the mode mode of of transportation. transportation. In In the the case case of of Africa, Africa, road road transportation transportation is is the the most most commonly commonly used means of transportation. The increasing population demand for alternative means of movement, used means of transportation. The increasing population demand for alternative means of movement, which which has has the the ∗ ∗
Corresponding Corresponding author. author. Tel.: Tel.: +27-74-252-6568 +27-74-252-6568 E-mail address: [email protected] E-mail address: [email protected]
2351-9789 2018 The The Authors. Authors. Published Published by by Elsevier Elsevier B. B. V. V. cc 2018 2351-9789 Peer-review under under responsibility of of theorganizing committee committee of of SMPM SMPM 2019. 2019. Peer-review 2351-9789 © 2019responsibility The Authors. theorganizing Published by Elsevier B.V. Peer-review under responsibility of the organizing committee of SMPM 2019. 10.1016/j.promfg.2019.05.069
472 2
I.D. Ibrahim et al. / Procedia Manufacturing 35 (2019) 471–476 I.D. Ibrahim et al / Procedia Manufacturing 00 (2018) 000–000
potentials to reduce road congestion, reduce the high volume of road crashes (which in some cases results to fatalities) and the extension in the lifespan of the road. South Africa as a country had their first and second train in the year 1860 (Durban) and 1862 (Cape Town) respectively [1]; electrification of rail was achieved in the 1920s. Since then, several improvements have been made to increase the performance, comfort and reduce the weight of the passenger train. The weight of the rail cars has a direct impact on the wearing rate of the rail tracks, the speed of the train and total carbon dioxide (CO2 ) emission. Therefore, arise the need to finding alternative materials that can be used to replace some of the interior components of the passenger trains. The alternative material should be sustainable having enhanced properties and that is where advance composite materials comes into the material mix. Advance composites materials have improved properties such high strength-to-weight, improve thermal performance, cost effective and moisture absorption rate [2]. 2. Materials and Method 2.1. Materials and Preparation The Council for Scientific and Industrial Research (CSIR) in Port Elisabeth, South Africa donated the sisal fiber and recycled polypropylene that was used for the research work. Improvement of the the sisal fiber strength was achieved by treating with 5% sodium hydroxide solution. The treatment was performed in a vacuum oven maintaining the temperature at 70 o C for 2 hours. The fiber was rinsed with water, 1% acetic acid solution and distilled water in that order to remove excess alkali. The treatment process and test samples are shown in Fig. 1. The treated fiber was left to dry for 24 hours at room temperature and was finally placed in a vacuum oven for 24 hours at a temperature of 60 o C. Cutting of the fiber was done to a length of approximately 5 mm. Organically modified montmorillonites (Cloisite30B) was supplied by Southern Clay Products Inc., USA, while Maleic anhydride grafted polypropylene (MAPP, FusabondP MZ 109D, DuPont) was supplied by Chemical Innovation Co., Ltd. Both materials were placed in the vacuum oven for 4 hours at 60 o C to remove moisture. 2.2. Method The melt blend approach was used. The premixing was done using HAAKE PolyLab OS Rheomix batch mixer (Thermo Electron Co., USA) with the following parameters: temperature of 200 o C, rotor speed of 60 rpm, for 8 minutes. The premixed polypropylene and MAPP were poured first into the Rheomix mixer, followed by the nanoclay and then sisal fiber. The MAPP was maintained at 5 %wt based on literature [3] while the nanoclay (1, 3 and 5 %wt) and fiber (10, 20, 30 and 40 %wt) were varied. The control sample was also prepared. The premixed samples were press moulded with the following parameters: temperature of 200 o C, pressure of 1500 psi and processing time of 8 minutes using Carver Laboratory Press. 3. Characterization 3.1. Mechanical Properties The mechanical properties (tensile strength and tensile modulus) were conducted using an Instron 5966 tester (Instron Engineering Corporation, USA) with a cross load cell of 10 kN, at a single strain rate of 5 mm/min according to ASTM D638. The presented results are average of five various tests. The impact testing was conducted using an Impactometer (Ceast, Italy) in line with ASTM D256 with a notch angle of 45o and depth of 2.5 mm. 3.2. Thermal Analyses The composites thermal behaviours were verified using a thermogravimetric analyser (TGA; TA Instrument, Model Q500, USA). Approximately 5 mg weight per sample was used. Heating rate was maintained at 10 o C/min starting from room temperature to 700 o C under air flow.
I.D. Ibrahim et al. / Procedia Manufacturing 35 (2019) 471–476 I.D. Ibrahim et al / Procedia Manufacturing 00 (2018) 000–000
473 3
Fig. 1. Fiber treatment (a) and (b), composites compounding (c), impact test samples (d) and tensile test samples (e)
3.3. Moisture Absorption The moisture absorption was studied by immersing the composite samples in water. The initial weights before and after immersing in water were measured. The percentage change in weight was determined using Equation 1. W=
(m f − mi ) × 100 mi
(1)
Where mi and m f are the initial weight before and after immersion in water respectively, W is the percentage water absorption. 4. Results and Discussion 4.1. Mechanical Properties Fig. 2 shows the tensile strength and modulus of the control sample and the reinforced polypropylene composites. From the figure it is observed that generally, fiber surface modification, incorporation of MAPP and nanoclay into polypropylene matrix showed noticeable improvement in the tensile strength and tensile modulus of all prepared composites. Little improvement was observed with the fiber treatment while further improvement was observed with the inclusion of 1 %wt nanoclay for tensile strength and tensile modulus compared to untreated sisal fiber reinforced composites. Similar observation was made by Chanprapanon et al. [4] for 1 %wt nanoclay inclusion with respect to
474 4
I.D. Ibrahim et al. / Procedia Manufacturing 35 (2019) 471–476 I.D. Ibrahim et al / Procedia Manufacturing 00 (2018) 000–000
Fig. 2. Tensile strength (a) and tensile modulus (b) of sisal fiber reinforced composites
Fig. 3. Impact strength of sisal fiber reinforced composites
tensile strength and tensile modulus of reinforced composites. Additional increase in nanoclay content led to further improvement in tensile strength and modulus, which was also reported by Lee et al. [5]. The improvement is due to proper nanoclay dispersion in the polymer matrix and fiber. Optimal tensile strength and modulus of 55.95(1.58) MPa and 1.7(0.17) GPa respectively was recorded based on the prepared samples when 5 %wt nanoclay was incorporated. Impact strength for the prepared samples are shown in Fig. 3. Fiber treatment led to an increase in impact strength compared with control sample. Incorporation of 1 %wt clay showed a reduction which is a result inadequate dispersion of the clay in the matrix. The impact strength showed much improvement of approximately 8.76(0.64) KJ/m2 with the incorporation of 5 %wt nanoclay.
I.D. Ibrahim et al. / Procedia Manufacturing 35 (2019) 471–476 I.D. Ibrahim et al / Procedia Manufacturing 00 (2018) 000–000
475 5
4.2. Thermal Analyses The thermal stability was observed to be lower with the composites containing treated fiber and MAPP when compared to the untreated sisal fiber reinforced polypropylene composites. This may be due to the presence of hemicellulose and lignin. The nanoclay inclusion further improved the thermal stability as shown in Table 1 which has been widely reported in literature, the inclusion of inorganic fillers into polymer matrix helped to improve thermal stability by absorbing and dissipating the heat energy entering the material [6][7][8]. Further increase was observed with additional increase in nanoclay contents. Table 1. Thermal properties of 40 %wt sisal fiber reinforced polypropylene composites Samples
T 5% (o C)
T 10% (o C)
T Max (o C)
Residue at 500o C
Control UT40/PP T40/PP T40/MAPP/PP T40/MAPP/C1/PP T40/MAPP/C3/PP T40/MAPP/C5/PP
301.88 274.45 271.30 262.64 262.80 265.76 282.11
323.01 293.70 294.69 281.83 285.75 288.27 306.87
379.79 370.90 351.97 350.39 351.89 352.54 394.14
4.044 3,413 3.327 2.943 4.748 8.919 16.83
UT: Untreated fiber, T: Treated fiber, C1: 1%wt clay, C3: 3%wt clay, C5: 5%wt clay T 5% : Temperature at 5% weight loss, T 10% : Temperature at 10% weight loss, T Max : Temperature at maximum decomposition.
4.3. Moisture Absorption The influence of treating the fiber, inclusion of compatibilizer on sisal reinforced composites is shown in Fig. 4. From the result, it was observed that very little water was absorbed by the control sample for the period of immersion, this is due to the hydrophobic nature plastic materials. The composite samples containing fibers were observed to absorb higher water, this was due to natural fibers hydrophilic nature. The fiber surface modification, filler inclusion and compatibilizer reduced the rate of water absorption of the fiber reinforced composites. Similar observation was reported by Mohan and Kanny [9]. The fiber surface treatment removed the presence of lignin, hemicellulose, wax and dirt which were responsible for the high level of water intake from the fiber-based polymer composites [10]. The inclusion of MAPP enhanced the adhesion between the matrix, filler and fiber due to good interfacial reaction that was created. 4.4. Conclusion The study presented the effect of fiber surface treatment, use of MAPP and incorporation of nanoclay to enhance the mechanical properties of reinforce polymeric composites applicable for the interior components of passenger trains. Conclusion from the study are presented as follows: • There was an improvement in the mechanical properties of composites treated with alkali solution. • MAPP and nanoclay inclusion further improved mechanical properties of sisal fiber reinforced composites. • Increase in fiber content led to increase in tensile strength, tensile modulus and impact strength of reinforced polypropylene composites. • Composite containing 5 %wt MAPP, 5 %wt nanoclay and 40 %wt treated fibers, showed the optimum mechanical properties based on the samples that were developed. • Thermal stability was observed to reduced when sisal fiber was introduced into the polymer. MAPP and nanoclay inclusion led to improvement in the thermal stability. • Significant decrease in water absorption was observed for composites containing treated fiber and nanoclay nanoparticle compared with the untreated fiber reinforced composites. Furthermore, increasing immersion time in water led to increase in water uptake fiber based composites.
I.D. Ibrahim et al. / Procedia Manufacturing 35000–000 (2019) 471–476 I.D. Ibrahim et al / Procedia Manufacturing 00 (2018)
476 6
Fig. 4. Water absorption rate of fiber reinforced composites
Acknowledgements Authors would like to thank the Tshwane University of Technology Pretoria, South Africa for providing a conducive environment to carry out this research work. Also wish to acknowledge the financial support from the CSIRDST Inter-Programme, South Africa, towards the research. The authors equally appreciate the financial support from Gibela, South Africa. References [1] [2] [3] [4] [5] [6] [7] [8] [9] [10]
M. Mitchell, Civil Engine. 2017 (2017) 68–70. I.D. Ibrahim, T. Jamiru, E.R. Sadiku, W.K. Kupolati, S.C. Agwuncha. J. Nanotechnol. (2016) http://dx.doi.org/10.1155/2016/4235975. N. Hamour, A. Boukerrou, A. Bourmaud, H. Djidjelli, Y. Grohens. Cellul. Chem. Technol. 50 (2016) 1069–1076 W. Chanprapanon, N. Suppakarn, K. Jarukumjorn. In Proceedings of the 18th International Conference on Composite Materials (ICCM11). August 2011. Y.H. Lee, T. Kuboki, C.B. Park, M. Sain, M. Kontopoulou. J. Appl. Polym. Sci. 118 (2010) pp.452–461. H. Alamri, I.M, Low, Z. Alothman. Composites: Part B. 43 (2012) 2762–2771. S.Y. Lee, I.A. Kang, G.H. Doh, W.J. Kim, J.S. Kim, H.G. Yoon and Q. Wu. eXPRESS Polym. Let. 2 (2008) 78–87. N.R. Paluvai, S. Mohanty, S.K. Nayak. J. Appl. Polym. Sci. 2015. DOI: 10.1002/APP.42068. T.P. Mohan, K. Kanny. Comp. Part A: Appl. Sci. Manuf. 43 (2012) 1989–1998. S. Kaewkuk, W. Sutapun, K. Jarukumjorn. Composites Part B: Engine. 45 (2013) 544–549.