Polypropylene hybrid composites filled by wood flour and short glass fiber: Effect of compatibilizer on structure and properties

Abstract

Polypropylene (PP) hybrid composites filled with wood flour (WF) and short glass fiber were prepared by melt blending and injection molding. Maleic anhydride-grafted PP (PP-g-MA), glycidyl methacrylate-grafted PP (PP-g-GMA), maleic anhydride-grafted ethylene-octene copolymer (POE-g-MA), and maleic anhydride-grafted hydrogenated styrene-butadiene-styrene (SEBS-g-MA) were used as the compatibilizers to enhance the interfacial adhesion between PP and the fillers. The effect of the types and contents of graft polymer on the crystallization and melting behavior, micromorphology, mechanical property, moisture resistance, and thermal stability of PP hybrid composites was observed. The result showed that PP-g-MA and PP-g-GMA had strong heterogeneous nucleation and promotion effect on PP crystallization. PP-g-MA was superior to enhance the tensile, flexural, and impact properties of composites. Hybrid composites had excellent moisture resistance and low water absorption. WF and PP macromolecular compatibilizer could improve the thermal stability of PP composites, in which the most obvious effect was obtained in PP-g-MA-modified WF and short glass fiber hybrid system. As a result, PP/WF composite could achieve outstanding improvement effect by being modified with macromolecular compatibilizer.