Surface-Modified Henequen/Polypropylene Biocomposites: E-Beam Intensity Effect on Their Interfacial Strength and Properties

摘要

In recent years, many researches have been performed with biocompositematerials fabricated using natural fibers as potential alternative of glass fiberreinforced polymer composites. The reasons for that are due to their advantages overglass fiber reinforcement, for instance, natural abundance, low cost, low density,biodegradability, carbon dioxide reduction in nature, acceptable specific engineeringproperties, damping and insulation characteristics, good processing stability, etc. Ingeneral, the interfacial strength between natural fibers and polymer matrix consistingof biocomposites is relatively weak because the surface of the natural fiber isintrinsically hydrophilic and the polymer resin is hydrophobic. Hence, many studieshave been devoted to improving the interfacial adhesion and the biocompositeproperties through various surface modification methods. In this study, henequennatural fibers without and with surface modification by electron beam (E-beam)irradiation were incorporated into a polypropylene matrix. Prior to biocompositefabrication, a bundle of raw henequen fibers were exposed to various E-beamintensities from 10 kGy to 500 kGy. The modified fibers were chopped to 10mm longin average. Polypropylene in the irregularly entangled fiber form, which can betransformed to the matrix in a mold by melting during composite processing, wasused. Various randomly oriented henequen/polypropylene biocomposites with thefiber contents of 40 vol% treated at different E-beam intensity were processed bycompression molding. The effect of E-beam intensity on the interfacial, mechanical,and thermal properties of the biocomposites was investigated focusing on theinterfacial shear strength, flexural and tensile properties, dynamic mechanicalproperties, thermal stability, and fracture surface observation. Each characteristic ofthe material strongly depended on the E-beam intensity irradiated, showing anincreasing or decreasing effect. The result agreed with each other among theirproperties studied.