Abstract
Wood fiber (WF) reinforced high-density polyethylene (HDPE) composite was prepared in this study. Due to the hydrophilicity of wood fiber and the nonpolar characters of the polyolefin matrix，chemical modification of wood fiber or resin matrix has been conducted to improve the interfacial compatibilization. Rheological properties of wood fiber reinforced HDPE composites were investigated. Results showed that the melt viscosity of wood fiber reinforced HDPE composites decreased as the processing temperature increased. Melt viscosity of composites increased with the fiber loading. The addition of wood fiber into HDPE resin can increase the tensile properties and flexural properties of resulted composites. However, the Izod notch impact strength decreases as the wood fiber content increases. Composites with coupling agent(Vinyltrimethoxysilane) or compatiblizer(High density polyethylene grafted maleic anhydryde) treatment posses better mechanical properties because of the good adhesion between wood fiber and polyolefin matrix，for example，the tensile strength of composite with 30wt% wood fiber content is increased from 27.38MPa to 39.78MPa. SEM microphotographs of the wood fiber/recycling HDPE composites were also investigated。The fracture surface of untreated wood fiber composites showed there are holes and fiber tip indicating that most of the fibers have been pulled-out without breaking during the fracture of untreated composite. This suggested the adhesion between the matrix and fiber is poor. The fracture surface of treated fiber composite showed fiber breakage rather than pull-out，and fibers were embedded in polymer matrix，which indicated better interfacial strength existed. Mechanical and rheological properties of wood fiber reinforced recycled HDPE composites were studied. Properties of polyolefin blend (PP/HDPE blend) were also investigated，results showed that the addition of POEgMA (polyolefin elastomer grafted maleic anhydride) compatibilizer could improve the flexural properties of composites.