| Abstract: | The pore characteristics and morphological changes of henequen fiber after electron beam (EB) irradiation were studied, and their effects on interfacial adhesion between henequen fiber and polypropylene (PP) matrix of biocomposites were investigated. The surface morphologies of the fibers exposed to various EB irradiation doses were observed with an atomic force microscope (AFM). The porosity and pore distribution of fibers were characterized by mercury porosimetry and nonfreezing bound water (NFW) was measured by differential scanning calorimeter (DSC). Henequen fiber-reinforced polypropylene biocomposites were manufactured by the compression molding method and interlaminar shear strength (ILSS) was analyzed to examine the interfacial adhesion between henequen fiber and the PP matrix of the biocomposites. The AFM images indicated that pectin, waxy materials and impurities were removed from the surfaces of the henequen fibers during EB irradiation, resulting in changes of the surface morphology and characteristics of the fibers. When pectin, waxy compounds and impurities were removed, small pores of 1–0.01 μm were produced, and total surface area and porosity were increased. The increase in total surface area and porosity induced better adhesion between fiber and polymer which was confirmed by ILSS tests. However, the excessive creation of small pore size gives a negative effect on the tensile strength of henequen fiber. The best interfacial adhesion between henequen fiber and PP was obtained for the biocomposite reinforced with the henequen fiber treated with 10 kGy, which has the highest surface area and optimum pore diameter for interlocking between henequen fiber and polypropylene. |
