Bio-based fibers (wood and bamboo)-filled high-density polyethylene composites were prepared in a twin-screw extruder using two types of coupling agents: maleated polyethylene and glycidyl methacrylate-grafted polyethylene. The effect of bio-fibers used as filler on the mechanical properties of composites was studied. It was observed that mechanical properties such as tensile and flexural strengths of the composites with coupling agent increased with increasing filler loadings. Tensile strength and flexural strength exhibited improvement up to 66% and 90%, respectively, over virgin high-density polyethylene. The maximum enhancement in the properties was observed with wood pulp when compared with wood- or bamboo flour-filled composites. Effect of coupling agents on the performance of composites was evaluated at 30% filler loading with wood flour as the filler. The study suggested that glycidyl methacrylate-grafted polyethylene exhibited better tensile and flexural properties as compared with maleated polyethylene. Impact strength of the composites prepared with coupling agent was found to be more than uncoupled composites. Among the fiber type, the impact strength of wood-fiber-filled composites was superior than that of bamboo flour-filled composites. Moisture absorption study indicated that even at 40% filler loading, moisture gain by the wood fiber- and bamboo flour-filled composites was merely 1.55% and 2.60% after 600 h of water immersion test, which suggests encapsulation of filler material by the polymer matrix.
KarnaniRKrishnanMNarayanR. Biofiber-reinforced polypropylene composites. Polymer Eng Sci1997; 37: 476–483.
2.
MaldasDKoktaBV. Improving adhesion of wood fiber with polystyrene by the chemical treatment of fiber with a coupling agent and the influence on the mechanical properties of composites. J Adhes Sci Technol1989; 3: 529–539.
3.
MaldasDKoktaBV. Interfacial adhesion of lignocellulosic materials in polymer composites: an overview. Compos Interfac1993; 1: 87–108.
4.
ChotorouHRiedlBAit-KadiA. Reinforced of recylcled polyolefins with wood fibers. J Reinf Plast Compos1992; 11: 372–394.
5.
LuJZWuQMcNabbHSJ. Chemical coupling in wood fiber and polymer composites: a review of coupling agents and treatments. Wood Fiber Sci2000; 32: 88–104.
6.
PracellaMChionnaDAnguillesiI. Functionalisation, compatibilisation and properties of polypropylene composites with hemp fibres. Compos Sci Technol2006; 66: 2218–2230.
7.
KarmarkarAChauhanSSModakJM. Mechanical properties of wood-fiber reinforced polypropylene composites: effect of a novel compatibilizer with isocyanate functional group. Compos Part A2007; 38: 227–233.
MaldasDKoktaBV. Influence of maleic anhydride as a coupling agent on the performance of wood fiber-polystyrene composites. Polymer Eng Sci1991; 31: 1351–1357.
10.
MahalbergRPaajanenLNurmiA. Effect of chemical modification of wood on mechanical and adhesion properties of wood fiber/polypropylene fiber and polypropylene/veneer composites. Holz als Roh-und Werkstoff2001; 59: 319–326.
11.
MyersGEChahyadiISGonzalecCWood flour and polypropylene or high-density polyethylene composites: influence of maleated polypropylene concentration and extrusion temperature on properties. In: WalcottMP (eds). Wood fibres/polymer composites: fundamental concepts, processes and material options, Madison, USA: Forest Product Society, 1993, pp. 49–56.
SailajaRRNChandaM. Use of maleic anhydride grafted polyethylene as compatibilisers for HDPE-tapioca starch blends: effect on mechanical properties. J Appl Polym Sci2001; 80: 863–872.
14.
Botros M and Chemicals E. Developments of new generation coupling agents for wood-plastic composites. In: Intertech conference the global outlook for natural and wood fiber composites, New Orland, LA, 3–5 December 2003, pp.1–14. Houston, TX: Equistar, Lyondell.
15.
KeenerTJStuartRKBrownTK. Maleated coupling agents for natural fiber composites. Compos Part A2004; 35: 357–362.
LeiYWuQYaoF. Preparation and properties of recycled hdpe/natural fiber composites. Compos Part A: Appl Sci Manufac2007; 38: 1664–1674.
19.
YangHSWolcottMPKimHS. Effect of different compatibilising agents on the mechanical properties of lignocellulosic material filled polyethylene bio-composites. Compos Struct2007; 79: 369–375.
20.
BouafitHKoubaaAPerreP. Effect of fiber characteristics on the physical and mechanical properties of wood plastic composites. Compos Part A2009; 40: 1975–1981.
21.
YemelaMCNKoubaACloutierA. Effect of bark fiber content and size on the mechanical properties of bark/HDPE composites. Compos Part A2010; 41: 131–137.
22.
BledzkiAKReihmaneSGassanJ. Thermoplastics reinforced with wood fillers: a literature review. Polym Plast Technol Eng1998; 37(4): 451–468.
23.
MaldasDKokataBVDaneaultC. Thermoplastic composites of polystyrene: effect of different wood species on mechanical properties. J Appl Polym Sci1989; 38(3): 413–439.
24.
Escobar WC. Influence of wood species on properties of wood/HDPE composites. PhD Thesis, Department of Civil and Environmental Engineering, Washington State University, USA, 2008.
25.
Zabihzadeh Seyed MajidForoogh DastoorianGhanbar Ebrahimi. Effect of Wood species and coupling agent on mechanical properties of wood flour/HDPE composites. J Reinf Plast Compos2010; 29: 1146–1152.
26.
StarkN. Influence of moisture absorption on mechanical properties of wood flour-polypropylene composites. J Thermoplast2001; 14: 421–431.
27.
RangarajSVSmithLV. Effect of moisture on durability of wood/thermoplastic composite. J Thermoplast Compos Mater2000; 13: 140–161.
28.
ASTM D638-94b. Tensile properties on plastics. Annual book of American Society for Testing and Materials (ASTM) standards, West Conshohocken, PA: ASTM, 1995.
29.
ASTM D790-92. Standard test method for flexural properties of unreinforced and reinforced plastics and electrical insulating materials. Annual book of American Society for Testing and Materials (ASTM) standards, West Conshohocken, PA: ASTM, 1995.
30.
ASTM D256-93a. Standard test method for impact resistance of plastics and electrical insulting materials. Annual book of American Society for Testing and Materials (ASTM) standards, West Conshohocken, PA: ASTM, 1995.
31.
Kamal B AdhikaryShusheng PangMark PStaiger. Dimensional stability and mechanical behaviour of wood–plastic composites based on recycled and virgin high-density polyethylene (HDPE). Compos Part B2008; 39(5): 807–815.
32.
KhanJAKhanMAKIslamR. Mechanical, thermal and interfacial properties of jute fabric-reinforced polypropylene composites: effect of potassium dichromate. Mater Sci Appl2010; 1: 350–357.
33.
LiXTabilLGPanigrahiS. The influence of fiber content on properties of injection molded flax fiber-HDPE biocomposites. Can Biosyst Eng2009; 148(8): 1–10.
34.
FaccaAGKortschotMTYanN. Predicting the tensile strength of natural fiber reinforced thermoplastics. Comos Sci Technol2007; 67: 2454–2466.
35.
Jayatilaka A. Composite materials-fiber reinforcement. Chapter 7. In: Fracture of engineering brittle materials. London: Applied Science Publishers, 1979, pp.216--280.
36.
MigneaultSKoubaAErchiquiF. Effect of fiber length on processing and properties of extruded wood-fiber/HDPE composites. J Appl Polym Sci2008; 110(2): 185–192.
37.
Rowell RM, Han JS and Rowell JS. Characterization and factors effecting fiber properties. In: Frolini E, Leao AL, Mattosso LHC (eds) Natural polymers and agrofibers composites, San Carlos, Brazil, 2000. pp.115–134.
38.
StarkNMRowlandsRE. Effect of wood fiber characteristics on mechanical properties of wood/polypropylene composites. Wood Fiber Sci2003; 35(2): 167–174.
39.
Chauhan SS. Knocking bamboo: a quick method to evaluate stiffness of bamboo in round form. In: Mandal AK, Berry N, and Rawat GS (eds) Proceedings of the national conference on bamboos: management, conservation, value addition and promotion. TFRI, Jabalpur, India, 12–14 March 2008, pp.223–233.
40.
FelixJMGatenholmP. The nature of adhesion in composites of modified cellulose fibers and polypropylene. J Appl Polym Sci1991; 42: 609–620.
41.
Pankaj K AggarwalN RaghuAjay Karmarkar. Jute-polypropylene composites using m-TMI-grafted-polypropylene as a coupling agent. Mater Des2013; 43: 112–117.
