PP/TLCP/GLASS FIBER HYBRID COMPOSITES Ⅰ : THE PREGENERATION OF TLCP FIBRILS AND CONTROL OF THE MORPHOLOGY OF HYBRID COMPOSITES

The effects of the drawing ratio and the addition of a compatibilizer on the morphology of dispersed thermotropic liquid crystalline polymer(TLCP) phase in the PP/TLCP in-situ composites were studied. The results show that a well-developed fibrils structure forms gradually with the increase of the drawing ratio after extrusion, and TLCP fibrils with large aspect ratios form in the composites at a relatively low drawing ratio with the introduction of PP-g-MAH as the compatibilizer. The obtained in-situ composites were further melt with glass fibers at 200℃ to be molded to a hybrid composite reinforced with glass fiber and TLCP fibrils. The microscopy investigation shows that the TLCP morphology is well maintained at this temperature. The typical skin-core structure of in-situ composites does not exist in the injected samples. The interfacial adhesion between glass fibers and PP matrix is enhanced by the addition of PP-g-MAH.