THE EFFECT OF INTERFACIAL MICROSTRUCTURE ON THE INTERFACIAL STRENGTH OF GLASS-FIBER POLYPROPYLENE RESIN COMPOSITES

In this study, a new method to form resin droplets on fibers has been developed, and samples for the single fiber pull-out test were prepare d using this method. The effects of microstructure of polypropylene (P P) resin and the microstructure of interface between the glass fiber a nd PP resin on the interfacial strength have been investigated. In add ition, the influence of the microstructure of the interface on the int erfacial strength of glass fiber-reinforced PP composites have been di scussed. It has been found that in the pull-out test, the transcrystal linity formed at the interface between the glass fiber and PP resin im proved the interfacial strength when no spherulites developed in the P P matrix. On the other hand, it has been found that when the spherulit es were well developed in the PP matrix, the transcrystallinity formed at the interface reduced the interfacial strength. Finally, rapid coo ling has been shown to improve the interfacial strength between the fi ber and resin in the crystalline polymer matrix composites. (C) John W iley & Sons, Inc.