Manufacturing of wood plastic composite from polyethylene/poly(ethylene terephthalate) waste/ultra high molecular weight polyethylene blends and rice husk fiber: Raw materials preparation and preliminary processing investigation

Abstract

The processing temperature of poly(ethylene terephthalate) waste (rPET) and ultra-high molecular weight polyethylene (UHMWPE) was lowered by blending to avoid decomposition of rice husk fiber (RHF) during the manufacturing of wood plastic composite (WPC). Maleic anhydride (MA) grafted blends of HDPE/LDPE/UHMWPE-g-MA and rPET/LDPE-MA were prepared. Those blends were flowable at 240 °C. They were employed as blended matrices to make HDPE/LDPE/UHMWPE-g-MA/rPET/LDPE-MA/RHF wood composite at processing temperatures not exceeding 240 °C. The study of RHF loading on the WPC performance revealed that melt flow index (MFI) and mechanical performances measured by impact, flexural, and tensile properties were weakened, but heat distortion temperature (HDT) was enhanced at high RHF loading. When the stabilizer content did not exceed 2 phf, the toughness and ductility were improved. Surface treatment of RHF by MA and dicumyl peroxide (DCP) enhanced the interfacial surface adhesion, but the toughness and ductility of the WPC were reduced at high MA/DCP dosing. The formation of crosslink structure via peroxide free radical initiated reaction at the MA grafted branch chains was the prime suspect for the inferiority of the mechanical performances.