Research on Moisture Absorption Behavior of Recycled Polypropylene Matrix Wood Plastic Composites

Abstract

To reduce the moisture absorption of wood fiber reinforced recycled plastic composites (WRPCs), coupling agent (KH550), methyl methacrylate (MMA), and maleic anhydride (MA) were used to modify the wood fibers in this work. The results indicated that the three different surface treatment methods could effectively reduce the moisture absorption and thickness swelling of WRPCs. Compared with the untreated wood fiber reinforced WRPCs, the moisture absorption ratios of WRPCs with wood fibers treated by KH550, MMA, and MA were reduced by 10.0%, 21.7%, and 27.6% respectively, the impact toughness was increased by 18.4%, 24.0%, and 2.1% respectively after 4 weeks’ immersion in hot water. The tensile strength of WRPCs was increased by 26.0% for KH550 and 11.1% for MA treatment respectively, but was decreased by 6.5% for MMA treatment. Coupling treatment of wood fibers was the best way to reduce the moisture absorption of WRPCs and this kind of WRPCs possessed the optimum comprehensive properties.