The Influence of Different Thermo-Mechanical Histories on the Crystalline Morphology of PET Fiber/iPP Composites

The interfacial morphology and the bulk morphological feature was investigated of PET fiber/iPP composites, which were prepared through different preparation methods by means of polarized optical microscope (POM). It was found that PET fibers directly introduced into the iPP melt present a quite strong α- nucleating ability. However, the nucleating ability of PET fibers and the bulk morphological features changed dramatically with the increasing of fiber content intended for the composites prepared through melt mixing in Haake internal mixer. Transcrystalline layer disappeared but the nucleating density in matrix increases steadily. Based on the experimental results above, different thermo-mechanical histories involved in sample preparation methods are proposed to be responsible for such phenomenon.