Effect of silane coupling on the fundamental properties of wood flour reinforced polypropylene composites

Abstract

Wood flour (WF) was chemically modified with silanes such as 3-aminopropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, and vinyltrimethoxysilane. Polypropylene (PP) composites reinforced with the chemically modified WF were prepared by melt compounding and injection molding. The effects of the silane treatments on the fundamental properties of wood fiber-reinforced PP composites were investigated by the measurement of mechanical properties, water absorption (WA), thermal properties, and scanning electron microscope (SEM) analysis. Silane treatments significantly improved tensile, flexural, and impact strengths of the composites, but it was found that there is no distinct difference among silanes. Silane treatments provided the decreased WA of the composites. From thermogravimetric analysis, the effect of the silane treatments on the thermal properties of the composites was not observed. From differential scanning calorimetric analysis, crystallization temperature and crystallization enthalpy were increased by the silane treatments, and crystallinity was decreased by the treatments. SEM photomicrographs show the evidence of the improved mechanical and WA properties of the PP/WF composites by the silane coupling treatments.