The Mechanical Properties of Natural Fibre Reinforced Polymer Composites: A Review

Download Full-Text PDF Cite this Publication

Text Only Version

The Mechanical Properties of Natural Fibre Reinforced Polymer Composites: A Review

Dr. Rajashekar Patil BOE Mechanical Department Reva School of Engineering

Reva University, Bangalore-560064 Karnataka, India

Ganesh Kalagi

Mechanical Department

Shri Madhwa Vadhiraja Institute of Technilogy Bantakal, Udupi-574115

Karnataka, India

Abstract Natural fibers have been used to reinforce materials for over 3,000 years. More recently they have been employed in combination with plastics. Many types of natural fibers have been investigated for use in plastics including Flax, hemp, jute, straw, wood fiber, rice husks, wheat, barley, oats, rye, cane (sugar and bamboo), grass reeds, kenaf, ramie, oil palm empty fruit bunch, sisal, coir, water hyacinth, pennywort, kapok, paper-mulberry, raphia, banana fiber, pineapple leaf fiber and papyrus. Natural fibers have the advantage that they are renewable resources and have marketing appeal. The Asian markets have been using natural fibers for many years e.g., jute is a common reinforcement in India. Natural fibers are increasingly used in automotive and packaging materials. Agricultural wastes include wheat husk, rice husk, and their straw, hemp fiber and shells of various dry fruits. These agricultural wastes can be used to prepare fiber reinforced polymer composites for commercial use.

This report examines the different types of fibers available and the current status of research. Many references to the latest work on properties, processing and application have been cited in this review.

Keywords Natural composites, polymers, hybrid fibres, mechanical properties.

  1. INTRODUCTION

    Composites are materials that comprise strong load carrying material (known as re-enforcement) imbedded in weaker material (known as matrix). Reinforcement provides strength and rigidity, helping to support structural load. The matrix or binder (organic or in-organic) maintains the position and orientation of the reinforcement. Significantly, constituents of the composites retain their individual, physical and chemical properties; yet together they produce a combination of qualities which individual constituents would be incapable of producing alone [1].

    Wood [2] is natural three-dimensional polymeric composite and consists primarily of cellulose, hemicelluloses and lignin.

    Historical examples of composites [3] are abundant in literature. Significant examples include the use of reinforcing mud walls in houses with bamboo shoots, glued laminated wood by Egyptians (1500 BC) and laminated metals in the forging of swords (1800 AD). In the 20th century, modern composites were used in 1930s, where glass fibers reinforced resins. Boats and aircrafts were built out of this glass

    composites, commonly called fiberglass. Since the 1970s, the application of composites has widely increased due to development of new fibers such as carbon, boron and aramids, and new composite systems with matrices made of metal and ceramics.

    Natural fibers have recently attracted the attention of scientists and technologists because of the advantages that these fibers provide over conventional reinforcement materials, and the development of natural fiber composites has been a subject of interest for the past few years. These natural [47] fibers are low-cost fibers with low density and high specific properties. These are biodegradable and nonabrasive, unlike other reinforcing fibers. Also, they are readily available and their specific properties are comparable to those of other fibers used for reinforcement.

  2. NATURAL FIBRE

    The use of natural fiber for the reinforcement of the composites has received increasing attention both by the academic sector and the industry. Natural fibers have many significant advantages over synthetic fibers. Currently, many types of natural fibers [8] have been investigated for use in plastics including fl ax, hemp, jute straw, wood, rice husk, wheat, barley, oats, rye, cane (sugar and bamboo), grass, reeds, kenaf, ramie, oil palm empty fruit bunch, sisal, coir, water, hyacinth, pennywort, kapok, paper mulberry, raphia, banana fiber, pineapple leaf fiber and papyrus. Thermoplastics reinforced with special wood [2] fillers are enjoying rapid growth due to their many advantages; light- weight reasonable strength and stiffness. Some plant proteins are interesting renewable materials, because of their thermoplastic properties. Wheat gluten [9] is unique among cereal and other plant proteins in its ability to form a cohesive blend with viscoelastic properties once plasticized. For these reasons, wheat gluten has been utilized to process edible or biodegradable films or packing materials. Hemp [10] is a bast lingo cellulosic fiber, comes from the plant Cannabis sativa and has been used as reinforcement in biodegradable composites.

    TABLE 1: MECHANICAL PROPERTIES OF NATURAL FIBRES [11]

    TABLE 2: NATURAL FIBRE PROPERTIES COMPARED TO E-GLASS [12]

    In the above table natural fibres are presented and compared to the properties of E-glass fibre. With respect to the natural fibres one has to keep in mind that large variation in properties exists due to natural circumstances.

    TABLE 3: ANNUAL PRODUCTION OF NATURAL FIBRE AND SOURCES

    Incorporation of hemp fibres into the polyester resin resulted in negligible improvement in tensile strength of the neat polyester resin but almost doubled the tensile modulus to 7.2 GPa. The addition of a small proportion of glass fibres to the hemp, producing a hybrid composite, resulted in almost 50% improvement in tensile strength and 10% improvement in tensile modulus.[13]

    The effects of chemical surface treatment on the hemp fibers and mechanical properties of hemp fiber composites were investigated. After chemical treatment of the fiber, the density and weight loss were measured. The surface morphologies of fibers were observed using SEM, and FT – IR was utilized to characterize the chemically modified fiber s. Among the tested samples, the 4 wt% NaOH- treated fiber composites demonstrated the best mechanical properties [13].

    Table4: The Density, Weight Loss and Tensile Strength of Hemp Fibre after Chemical Treatments

    The tensile properties of natural fiber reinforce polymers (both thermoplastics and thermosets) are mainly influenced by the interfacial adhesion between the matrix and the fibers. Several chemical modifications are employed to improve the interfacial matrixfiber bonding resulting in the enhancement of tensile properties of the composites. In general, the tensile strengths of the natural fiber reinforced polymer composites increase with fiber content, up to a maximum or optimum value, the value will then drop. However, the Youngs modulus of the natural fiber reinforced polymer composites increase with increasing fiber loading. The tensile strength and Youngs modulus of composites reinforced with bleached hemp fibers increased incredibly with increasing fiber loading[15].

    Natural fibers are potentially a high-performance non- abrasive reinforcing fiber source. In this study, pulp fibers [including bleached Kraft pulp (BKP) and thermo mechanical pulp (TMP)], hemp, flax, and wood flour were used for reinforcing in polypropylene (PP) composite. The results show that pulp fibers, in particular, TMP-reinforced PP has the highest tensile strength, possibly because pulp fibers were subjected to less severe shortening during compounding, compared to hemp and flax fiber bundles[16].

    With introduction of 5 layered hemp reinforcement (26% fibre volume fraction) into the polyester, the peak load and total energy aborbed no longer increased but decreases slightly compared to 4 layered (21% fibre volume fraction) of hemp reinforcement. This trend of decreasing peak load and total absorbed energy would be expected to continue if an additional layer of hemp was introduced. [17]

    This may be due to the resin being less able to wet the fibres. This indicates that the threshold fibre volume fraction of this composite system is approximately 21%. Beyond this, the load bearing and energy absorption capabilities of the composite system would not increase even if the volume fraction of the fibre reinforcement were increased. [17]

    The strength and stiffness of hemp fibre reinforced unsaturated polyester composites in this study were found to be lower than comparable chopped strand E-glass fibre reinforced polyester composites. However, the impact test results show that the total impact energy absorbed by 21% fibre volume (4 layered) hemp rein-forced specimen is comparable to the total energy absorbed by 21% fibre volume chopped strand mat E-glass reinforced specimens.[17]

    The mechanical behavior high density polyethylene (HDPE) reinforced with continuous henequen fibres (Agave fourcroydes) was studied.[18]

    It was observed that the increase in stiffness from the use of henequen fibres was approximately 80% of the calculated values. The increase in the mechanical properties ranged between 3 and 43%, for the longitudinal tensile and flexural properties, whereas in the transverse direction to the fibre, the increase was greater than 50% with respect to the properties of the composite made with untreated fibre composite. In the case of the shear strength, the increase was of the order of 50%. From the failure surfaces it was observed that with increasing fibre-matrix interaction the failure mode changed from interfacial failure to matrix failure. [18]

    Fig1: effect of various fibre treatments on the tensile strength of HDPE- henequene composites. [18]

    Fig2: effect of various fibre treatments on the tensile modulus of HDPE- henequene composites. [18]

    Fig3: effect of various fibre treatments on the flexural strength of HDPE- henequene composites. [18]

    Fig4: effect of various fibre treatments on the flexural modulus of HDPE- henequene composites. [18]

    The mechanical properties of the natural fibre composites tested were found to compare favorably with the corresponding properties of glass mat polypropylene composites. The specific properties of the natural fibre composites were in some cases better than those of glass. This suggests that natural fibre composites have a potential to replace glass in many applications that do not require very high load bearing capabilities. [19]

    Fig5: tensile strength of Fibre reinforced polymer composites [19]

    Fig6: flexural strength of Fibre reinforced polymer composites [19]

    Fig7: charpy impact strength of fibre reinforced polymer composites [19]

    The experiments are carried out to determine tensile, flexural and impact properties of jute and hemp reinforced with epoxy and polyester hybrid composites for 30o, 45o, and 90° fibre orientations. From the obtained results following conclusion have been drawn. [20]

    Composite with polyester resin as matrix give more tensile, flexural and impact strength than epoxy based hybrid composites. [20]

    The tensile, flexural and impact strength is observed to be maximum at 90° orientation in both epoxy and polyester based composites. [20]

    Composite rotor blade built from flax/polyester and E-glass/polyester has been investigated. It is found that the flax/polyester blade is 10% lighter than the E-glass/polyester blade (fiber mass saving 45%). In conclusion it was proposed that flax is suitable structural replacement to E-glass for similar composite small wind turbine blade applications. [21]

  3. TECHNICAL APPLICATIONS OF NATURAL FIBER REINFORCED COMPOSITES

    Natural fibers are replacing synthetic fibers as reinforcement in various matrices. The composites so prepared can effectively be used as substitute for wood and also in various other technical fields, e.g. automotive parts.

    Seventy years ago, nearly all resources for the production of commodities and many technical products were materials derived from natural textiles. Textiles, ropes, canvas and also paper, were made of local natural fibers, such as flax and hemp. Some of these are still used today. As early as 1908, the first composite materials were applied for the fabrication of large quantities of sheets, tubes and pipes for electronic purposes (paper or cotton to reinforce sheets, made of phenol or melamine-formaldehyde resins). For example in 1996, aero plane seats and fuel tanks were made of natural fibers with small content of polymeric binders. The last decade has seen a multiplicity of applications of natural fiber composites due to their impressive properties such as biodegradability and high specific properties. Currently, a revolution in the use of natural fibers, as reinforcements in technical application, is taking place mainly in the automobile and packaging industries (e.g., egg boxes). In the automotive industry, textile waste has been used for years to reinforce plastics used in cars, especially in the Trabant.

    The use of natural fibers within composite applications is being pursued extensively throughout the world. Consequently, natural fiber composite materials are being used for making many components in the automotive sector. These materials are based largely on polypropylene or polyester matrices, incorporating fibers such as flax, hemp, and jute. Thus in the future cars may be molded from cashew nut oil and hemp. Even golf clubs may be built around jute fibers, and tennis racket may be stiffened with coconut hair. Bicycle frames may derive their strength from any one of the 2000 other suitable plants. The high-tech revolution in use of natural fibers could end in replacement of synthetic materials.

    The diverse range of products now being produced, utilizing natural fibers and biobased resins derived from soybeans, is giving life to a new generation of biobased composites for a number of applications. These include not only automotive vehicles (including trucking) but also hurricane-resistant

    housing and structures, especially in the United States [22]. The construction sector and the leisure industry are some of the other areas where these novel materials are finding a market. In Germany, car manufactures are aiming to make every component of their vehicles either recyclable or biodegradable [23].

  4. CONCLUSION

    Natural fibers, when used as reinforcement, compete with such technical fibers as glass fiber. The advantages of technical fibers are good mechanical properties; which vary only little, while their disadvantage is difficulty in recycling. Several natural fiber composites reach the mechanical properties of glass fiber composites, and they are already applied, e.g., in automobile and furniture industries. Till date, the most important natural fibers are Jute, flax and coir. Natural Fibers are renewable raw materials and they are recyclable.

  5. REFERENCES

  1. Hull, D. and Clyne, T.W. 1996. An introduction to composite materials. Cambridge University Press, Cambridge

  2. Bledzki, A. K., Reinhmane, S. and Gassan, J. 1998.Thermoplastics reinforced with wood fi llers. Polym Plast. Technol. Eng. 37:451- 468.

  3. Chawla, K.K. 1987. Composite Materials. Science and Engineering. Springer-Verlag,Newyork.

  4. Schneider, J. P.; Myers, G. E.; Clemons, C. M.; English,B. W. Eng Plast 1995, 8 (3), 207.

  5. Reinforced Plastics 1997, 41(11), 22.

  6. Colberg, M.; Sauerbier, M. Kunstst-Plast Europe 1997, 87(12), 9.

  7. Schloesser, Th.; Knothe, J. Kunstst-Plast Europe 1997, 87 (9),

  8. Bledzki, A.K. and Gassan, J. 1999. Composites reinforced with cellulose based fi bers. Prog. Polym. Sci. 24:221-274.

  9. Marion, P., Andréas, R. and Maie, H.M. 2003. Study of wheat gluten plasticization with fatty ac-ids. Polym. 44:115-122.

  10. Mwaikambo, L.Y. and Ansell, M.P. 2003. Hemp fi ber reinforced cashew nut shell liquid composites.

  11. Maya Ja cob John,Rajesh D. Ana ndjiwa la, A rescent developments in chemical modifications and charecterization of natural fibre reinforced composites

  12. Mehdi Tajvidi Static and Dynamic Mechanical Properties of a Kenaf FiberWood Flour/Polypropylene Hybrid Composite, DOI 10.1002/app.22093.

[13]A. Shahzad, D.H. Isaac and S.M. Alston, Mechanical Properties of Natural Composites

  1. Suardana, Yingjun Piao, Jae Kyoo LimMechanical properties of Hemp fibres and Hemp/PP Composites: Effects of chemical surface treatmnet. December 2010

  2. H. Ku, H. Wang, N. Pattarachaiyakoop, M. Trada, A review on tensile Properties of natural fibre reinforced polymer composites.

  1. H.N. Dhakal, The low velocity impact response of non-woven hemp fibre reinforced unsaturated polyester composites.

  2. P.J.Herrera-Franco, Mechanical properties of continuous

    naturalfibre reinforced polymer composites. Composites: Part A 35 (2004)339345

  3. Paul Wambua, Natural fibre: can they replace glass in fibre reinforced plastics? Composites Science and Technology 63 (2003) 12591264

  4. Girisha K G, Mechanical properties of jute and hemp reinforced epoxy/polyester hybrid composites Vol2, issue 4, Apr 2014, 245-248

  5. Darshil U Shah, Can flax replace E-glass in structural composites? A Small Wind turbine blade case study (2013) 172-18

  6. Rowel, R.M., Sanadi, A.R., Caul fi eld, D.F. and Jacobson, R.E. 1997. Utilization of natural fibers in composites: problems and opportunities in ligno-cellulosic-plastic composites. Eds. Leao, A., Carv-alho, F.X. and Frollini, E., USP/UNESP Publishers, Sao Paulo. pp. 23-51.

  7. Hanselka, H., Herrmann, A.S. and Promper, E. 1995. Automobil- Leichtban durchden Einsatz Von (biologisch adbanbaren) Naturfaser- verbundwerk-stoffen, VDI Berichte Nr.1235

  8. Maldas, D., Kokta, B.V. and Daneault, C. 1989. Composites of polyvinyl chloride-wood fibers. IV. Effect of the nature of fibers. J. Vinyl Technol. 11:90-99.

  9. Maldas, D. and Kokta, B.V. 1993. Performance of hybrid reinforcement in PVC composites. J. Test. Eval. 2:68-72.

  10. Hedenberg, P. and Gatenholm, P. 1995. Conver-sion of plastic/cellulose waste into composites. J. Appl. Polym. Sci. 56:641- 651.

  11. Yam, K.L., Gogoi, B.K., Lai, C.C., and Selke, S.E. 1990. Composites from compounding wood fibers with recycled high density polyethylene.Polym. Eng. Sci. 30:693-699.

  12. Sain, M.M., Imbert, C. and Kokta, B.V. 1993. Composites of surface treated wood fiber and re-cycled polypropylene. Angew. Makromol. Chem. 210:33-46.

  13. Mallick, P.K. 1993. Fiber reinforced composites. Marcel Dekker, New York.

  14. Bledzki, A.K. and Gassan, J. 1999. Composites reinforced with cellulose based fibers. Prog. Polym. Sci. 24:221-274.

  15. Marion, P., Andréas, R. and Marie, H.M. 2003. Study of wheat gluten plasticization with fatty ac-ids. Polym. 44:115-122.

  16. Mwaikambo, L.Y. and Ansell, M.P. 2003. Hemp fiber reinforced cashew nut shell liquid composites. Compos. Sci. Technol. 63:1297- 1305.

  17. Jiang, L. and Hinrichsen, G. 1999. Flax and cot-ton fiber reinforced biodegradable polyester amide. Die Angew. Makromol.Chem. 268:13- 17.

  18. Rowell, R.M., Young, R.A. and Rowell, J.K. 2002. Paper and composites from Agro-based re-sources. CRC Press. Boca Raton, F.L.

  19. Harriette, L.B., Jorg, M. and Martie, J.A. 2006. Mechanical properties of short-flax-fiber reinforced compounds. Compos: A 37:1591-1604.

  20. Yang, H.S., Kim, H.J., Lee, B.J. and Hawng, T.S. 2004. Rice husk flour filled polypropylene compos-ites; mechanical and morphological study. Compos. Struct. 63:305-312 .

  21. Yang, H.S., Kim, H.J., Lee, B.J. and Hawng, T.S. 2007. Effect of compatibilizing agent on rice husk flour reinforced polypropylene composites. Com-pos. Struct. 77:45-55.

  22. Hornsby, P.R., Hinrichson, E. and Trivedi, K., 1997. Preparation and properties of polypropylene composites reinforced with wheat and flax straw fibers. Part 1. Fiber characterization. J. Mater. Sci. 32:443- 449.

  23. Hornsby, P.R., Hinrichson, E. and Trivedi, K. 1997. Preparation and properties of polypropylene composites reinforced with wheat and flax straw fi-bers. Part. 2. Analysis of composite microstructure and mechanical properties. J. Mater. Sci. 32:1009-1015.

  24. Panthapulakkal, S., Zereshkian, A. and Sain, M. 2006. Preparation and characterization of wheat straw fibers for reinforcing application in injection molded thermoplastic composites. Biores Technol. 97:265- 272

  25. Karmaker, A.C. and Youngquist, J.A. 1996. In-jection moulding polypropylene reinforced with short jute fibers. J. Appl. Polym. Sci. 62:1142-1151.

  26. Rana, A.K., Mitra, B.C. and Banerjee, A.N. 1999. Short jute fiber reinforced polypropylene composites: dynamic mechanical study. J. Appl. Polym. Sci.71:531-539.

  27. Rajulu, A.V., Baksh, S.A., Reddy, G.R. and Chary, K.N. 1998. Chemical resistance compos-ites. J. Reinforced Plast. Compos. 17:1507-1511.

  28. Chen, X., Gao, Q. and Mi, Y. 1998. Bamboo Fi-ber-reinforced polypropylene composites: a study of the mechanical properties. J. Appl. Polym. Sci. 69:1891-1899.

  29. Thwe, M.M. and Liao, K. 2002. Effects of envi-ronmental aging on the mechanical properties of bamboo-glass fiber reinforced polymer matrix hy-brid composites. Composites Part A. 33:43-52.

  30. Okubo, K., Fujii, T. and Yamamoto, Y. 2004. De-velopment of bamboo-based polymer composites and their mechanical properties. Composites Part A 35:377-383.

  31. Wambua, P., Ivens, U. and Verpoest, I. 2003. Natural fibers: can they replace glass in fiber-re-inforced plastics? Compos. Sci. Technol. 63:1259-1264.

  32. Larbig, H., Scherzer, H., Dahlke, B, and Pol-trock, R. 1998. Natural Fiber reinforced foams based on renewable resources for automotive

    inte-rior applications. J. Cellular Plast. 34:361-379.

  33. Vazguez, A., Riccieri, J. and Carvalho, L. 1999. Interfacial properties and initial step of the water sorption in unidirectional unsaturated polyester/ vegetable fiber composites. Polym. Compos. 20:29-37.

  34. Luo, S. and Netravali, A. 1999. Mechanical and thermal properties of environment-friendly greencomposites made from pineapple leaf fibers and poly (hydroxybutyrate-co-valerate) resin. Polym. Compos. 20:367-78.

  35. Ràczs, I. and Hargitai, H. 2000. Influence of water on properties of cellulosic fiber reinforced polypropylene composites. Int. J. Polym. Mater. 47:667-674.

  36. Dale, E.W. and ODell, J.L. 1999. Wood-poly-mer composites made with acrylic monomers, iso-cyanate and maleic anhydride. J. Appl. Polym. Sci. 73:2493-505.

  37. Patil, Y.P., Gajre, B., Dusane, D. and Chavas, S. 2000. Effect of maleic anhydride treatment on steam and water absorption of wood polymer com-posites prepared (12): heat straw, cane bagasse, and teakwood sawdust using novolac as matrix. J. Appl. Poly. Sci. 77:2963-2967.

  38. Bledzki, A.K., Reihmane, S. and Gassan, J. 1998. Thermoplastics reinforced with food fillers: a literature review; Polym. Plast Technol. Eng. 27: 451-468.

  39. Mani, P. and Satyanarayan, K.G. 1990. Effects of he surface treatments of lignocellulosic fibres on their debonding stress. J. Adh. Sci. Technol. 4:17-24.

  40. Mitra, B.C., Basak, R.K. and Sarkar, M. 1998. Studies on jute- reinforced composites, its limita-tions, and some solution through chemical modi-fications of fibers. J. Appl. Polym. Sci. 67:1093-1100.

  41. Samal, R.K. and Ray, M.C. 1997. Effect of chem-ical modification on FTIR-spectra and physico-chemical behavior of pneapple bead fibre. J. Poly. Mater. 14:183-188.

  42. Joseph, K., Thomas, S. and Pavithran, C. 1996 Effect of chemical treatment on the tensile prop-erties of short sisal fibre-reinforced polyethylene composites. Polymer 37:5139-5149.

  43. Selke, S., Yam, K. and Nieman, K. ANTEC89. Society of Plastics Engineers, pp. 1813-1815.

  44. Dalvag, H., Kalson, C. and Stromvall, H.S. 1985. The efficienty of cellulosic fillers in common ther-moplastics. 2. Filling with processing aids and cou-pling agents. Int. J. Polym. Mater. 11 (1):9- 38.

  45. Catellano, M., Gandini, A., Fabbri, P. and Bel-gacem, M.N. 2004. Modification of cellulose fibres with organosilanes: under what conditions does coupling occur? J. Colloid Inter. Sci. 273:505-511.

  46. Jensena, R.E., Palmeseb, G.R. and Mcknighta, S.H. 2006. Viscoelastic properties of alkoxy silane-epoxy interpenetrating networks. Int. J. Adh. Ad-hes. 26:103-115.

  47. Laly, A.P. and Sabu, T. 2003. Polarity parameters and dynamic mechanical behaviour of chemically modified banana fiber reinforced polyester com-posites. Comp. Sci. Tech. 63:1231-1240.

  48. Herrera-Franco, P.J. and Valadez-Gonzalez, A. 2005. A study of the mechanical properties of short natural-fiber reinforced composites.

    Composites B 36:597-608. Natural fiber-reinforced composites

  49. Abdelmouleh, M., Boufi, S., Ben Salah, A., Bel-gacem, M.N. and Gandini, A. 2002. Interaction of silane coupling agents with cellulose. Langmuir 18:3203.

  50. Abdelmouleh, M., Boufi, S., Belgacem, M.N., Duarte, A.P., Ben Salah, A. and Gandini, A.

    2004. Modification of cellulosic fibers with func-tionalized silanes: development of surface proper-ties. Int. J. Adh. Adhes. 24:43-54.

  51. Abdelmouleh, M., Boufi, S., Belgacem, M.N., Dufresne, A. and Gandini, A. 2005. Modification of cellulose fibers with functionalized silanes: ef-fect of the fiber treatment on the performance of cellulose- thermoset composites. J. Appl. Poly. Sci. 98:974-984.

  52. Abdelmouleh, M., Boufi, S., Belgacem, M.N., Dufresne, A. and Gandini, A. 2007. Short natural- fiber reinforced polypropylene and natural rubber composites: Effect of silane coupling agents and fiber loading. Comp. Sci. 67:1627-1639.

  53. Gassan, J. and Bledzki, A. 1999. Effect of cyclic moisture absorption desorption on the mechani-cal properties of silanized jute-epoxy composites. Polym. Compos. 20:604-611.

  54. Tripathy, S. Mishra, S. and Nayak, S. 1999. Nov-el, low cost jute- polyester composites. Part 1: pro-cessing, mechanical properties, and SEM analysis. Polym. Compos. 20:62-71.

  55. Mishra, S., Naik, J. and Patil, Y. 2000. The com-patibilising effect of maleic anhydride on swell-ing and mechanical properties of plant- fiber-rein-forced novolac composites. Compos. Sci. Technol. 60:1729-

    1735.

  56. Netravali, A. and Luo, S. 1999. Interfacial and mechanical properties of environment-friendly green composites made from pineapple fibers and poly (hydroxybutyrate-co-valerate) resin. J. Mater. Sci. 34:3709- 3719.

  57. Gauthier, R., Joly, C., Campas, A., Gaultier, H. and Escoubes, M. 1998. Interfaces in polyolefin/ cellulosic fiber composites: chemical coupling, morphology, correlation with adhesion and aging in moisture. Polym. Compos. 19:287-300.

  58. Mwaikambo, L. and Ansell, M. 2002. Chemical modification of hemp, sisal, jute and kapok fibers by alkalisation. J. App. Polym. Sci. 84:2222-2234.

  59. Wambua, P., Vangrimde, B., Lomov, S. and Ver-poest, I. 2007. The response of natural fiber com-posites to ballistic impact by fragment simulating projectiles. Compos. Struct. 77:232-240

  60. DAlmeida, J.R.M., Nunes, LM. and Paciornik, 2004. Evaluation of the damaged area of glass-fiber-reinforced epoxy-matrix composite materials submitted to ballistic impacts. Compos. Sci. Tech-nol. 64:945-954.

  61. Hasur, M.V., Vaidya, U.K., Ulven, C. and Jee-lani, S. 2004. Performance of stitched/unstitched woven carbon/epoxy composites under high veloc-ity impact loading. Compos. Struct. 64:455-466.

  62. Lee, B.L., Walsh, T.F., Won, ST. and Patts, H.M. 2001. Penetration failure mechanisms of armour-grade fiber composites under impact. J. Compos. Mater. 35:1605-1633.

  63. Chou, S.C., DeLuca, E., Prifti, J. and Betheney, 1998. Ballistic impact damage of S2-glass-rein-forced plastic structural armor. Compos. Sci. Tech-nol. 1453-61.

  64. Hine, P.H., Duckett, R.A., Morye, S.S., Carr, D.J, and Ward, I.M. 2000. Modeling of the en-ergy absorption by polymer composites upon bal-listic impact. Compos. Sci. Technol. 60:2631-2642.

  65. Cantwell, W.J., and Villanueva, G.R. 2004. The high velocity impact response of composite and FML-reinforced sandwich structures. Compos. Sci. Technol. 64:35-54.

  66. Rowel, R.M., Sanadi, A.R., Caulfield, D.F. and Jacobson, R.E. 1997. Utilization of natural fibers in composites: problems and opportunities in ligno-cellulosic-plastic composites. Eds. Leao, A., Carv-alho, F.X. and Frollini, E., USP/UNESP Publishers, Sao Paulo. pp. 23-51.

  67. Hanselka, H., Herrmann, A.S. and Promper, E. 1995. Automobil- Leichtban durchden Einsatz Von (biologisch adbanbaren) Naturfaser- verbundwerk-stoffen, VDI Berichte Nr.1235.

  68. Kenning, D. 2003. (Splendid Engineering Ltd.) The splendid Eco car project, presentation at Sus Comp Net 4. Queen Mary and Westfield College, London.

  69. Zadorecki, P. and Foldin, P. 1986. Surface modi- fication of cellulose fibres. III. Durability of cellu-lose-polyster composites under environmental ag-ing. J. Appl. Polym. Sci. 31:1966-1970.

  70. Maldas, D. and Kokta, B.V. 1990. Influence of phthalic anhydride as a coupling agent on the me-chanical behaviour of wood fiber- polystyrene com-posites. J. Appl. Polym. Sci. 41:185-194.

  71. Razi, P.S., Portier, R. and Raman, A. 1999. Stud-ies on polymer-wood interface bonding: effect of coupling agents and surface modification. J. Com-pos. Mater. 33:1064-1079.

  72. Belgacem, M.N., Bataille, P. and Sapieha, S. 1994. Effect of corona modification on the mechan-ical properties of polypropylene/cellulose compos-ites. J. Appl. Polym. Sci. 53:379-385.

  73. Sakata, I., Morita, M., Tsuruta, N. and Morita, 1993 Activation of wood surface by corona treatment to improve adhesive bonding. J. Appl. Polym. Sci. 49:1251-1258.

  74. Wang, Q., Kaliaguine, S. and Ait-Kadi-A. 1993. Catalytic grafting A new technique for poly-mer fiber composites 3. Polyethylene plasma treat-ed Kevlar(TM) fibers composites analysis of the fiber surface.

    J. Appl. Polym. Sci. 48:121-136.

  75. Panthapulakkal, S., Sain, M. and Law, L. 2005. Effect f coupling agents on rice-husk-filled HDPE extruded profiles. Polym. Int. 54:137-142.

  76. Keener, T.J., Stuart, R.K. and Brown, T.K. 2004. Maleated coupling agents for natural fiber compos-ites. Composites A 35:357-362.

  77. Wulin, Q., Farao, Z., Endo, T. and Hirotsu, T. 2005. Isocyanate as a compatiabilzing agent on the properties of highly crystalline cellulose/polypro-pylene composites. J. Mater. Sci. 40:3607-3614.

  78. Colom ,X., Carrasco, F., Pagec P. and Cana-vate, J. 2003. [78] Effects of different treatments on the interface of HDPE/lignocellulosics fibre compos-ites. Compos. Sci. Tech. 63:161-

    169.

  79. Demir, H., Atiklera, U., Balkosea, D. and Ti-hminhoglua, F. 2006. The effect of fiber surface treatments on the tensile and water sorption proper-ties of polypropylene-luffa fiber composites. Com-posites A.37: 447-456.

  80. Valadez, G.A., Cervantes, U., Olayo, R. and Herrera-Fraco, P. 1999. Chemical modification of henequen fibers with an organosilane coupling Agent.

  81. Mishra S, Naik J, Patil Y. The compatibilising effect of maleic anhydride on swelling and mechanical properties of plant-fibre- reinforced novolac composites. Composites Science and Tech-nology 2000;60:172935.

  82. Netravali A, Luo S. Interfacial and mechanical properties of environment-friendly green composites made from pineapple fibres and poly(hydroxybutyrate-co-valerate) resin. Journal of Materials Science 1999;34:370919.

  83. Gauthier R, Joly C, Compas A, Gaultier H, Escoubes M. Inter-faces in polyolefin/cellulosic fibre composites: chemical coupling, morphology, correlation with adhesion and aging in moisture. Polymer Composites 1998;19(3):287300.

  84. Beukers A. In: Van Hinte, editor. Lightness, the inevitable renaissance of minimum energy structures. Rotterdam: 010 pub- lishers; 1999. p. 72.

  85. Lee N-J, Jang J. The effect of fibre content on the mechanical properties of glass fibre mat/polypropylene composites. Compo- sites:Part A1999;30:81522.

  86. SimsG D, Broughton WR. In: KellyA,Zweben C, editors.Glass fibre reinforced plastics-properties. Comprehensive composite materials, vol. 2. 1st ed. London: Elsevier; 2000. p. 165

Leave a Reply

Your email address will not be published. Required fields are marked *