Mechanical Property and Degradation in Hot Water of Injection Molded Glass Short Fiber/Wood Powder/Polypropylene Hybrid Composites

As well known, natural fibers absorb water easily that will affect the mechanical property considerably and there exists a problem of incompatibility which leads the weak interfacial adhesion between the fiber and the resin matrix because of the hygroscopic nature of natural fibers. Therefore, conducting hot water immersion and tensile test is necessary to study the mechanical property and degradation. In this study, glass fiber/wood powder/pp. hybrid composites were prepared by injection molding process at a fixed reinforcement to matrix ratio of 51:49. 3 kinds of hybrid specimens with glass fiber/wood powder ratios of 51:0, 21:30, and 0:51 were fabricated. The hydrothermal aging performance was investigated during the 80°C hot water immersion experiment with a series of immersion time and the effect of hot water immersion on the mechanical properties of composites have been evaluated based on the tensile test. Results showed that both the strength and modulus of hybrid composite decrease obviously as the immersion time increase, which can be considered that the hydroscopic property of natural fiber would decrease the durability of composite in humidity environment. And the skin-core structure comes from injection molded process contributes to the better hydrothermal aging property of Glass/PP composite.