Mechanical Properties of Injection Molde Silk Fiber/Polypropylene Composites

Recently attention has been given to shift from glass fiber and carbon fiber to natural fibers as reinforcement for FRP composites with the goal of protect of the environment. This paper concerned with the application of raw silk fiber to reinforcement for composite material. In this study, polypropylene (PP) resin was used for the matrix material and the composites were molded using the injection-molding method. Maleic anhydride grafted polypropylene (MAPP) was also used as the binder resin.Mechanical properties of Silk/PP composites were discussed and compared with standard glass fiber reinforced plastics (GFRP). Furthermore, detailed SEM observation of the cross-section of each molded composite was carried out . As a result, the tensile strength and elastic modulus were found to increase with increasing silk fiber content. In particular, the Izod impact value for the Silk/PP composite was the same as that of GFRP. Moreover, good adhesion between the silk fiber and matrix material was achieved through use of MAPP due to the good reaction between MAPP and the hydroxy groups and amino groups of the silk fiber. However, the dispersion of raw silk fiber was relatively poor in comparison with that of glass fiber in the molded composites.