EFFECT OF MOLECULAR-WEIGHT AND FIBER DIAMETER ON THE INTERFACIAL BEHAVIOR IN GLASS FIBER PP COMPOSITES/

In this study, the effects of fiber diameter, molecular weight of the matrix polymer, and interfiber spacing in glass fiber-reinforced polyp ropylene composites were investigated on the interfacial microstructur e. The influences of the surface state of the fiber and the heat-treat ment condition on the interfacial morphology and the spherulitic forma tion process in the matrix were also investigated. Consequently, it wa s found that both the fiber diameter and molecular weight of the polym er significantly influence the thickness of the transcrystalline layer . Also, as the interfiber spacing becomes smaller, the spherulites in the matrix polymer are not seen to be formed between the transcrystall ine layers developed on the glass-fiber surface. In addition, the radi us of the largest spherulites in the matrix polymer was found to be ab out the same as the thickness of transcrystalline region and to largel y depend on the holding time at the crystallization temperature and co oling condition (or rate). (C) 1998 John Wiley & Sons, Inc.