原位成纤复合法改善聚丙烯的力学性能

Improvement of mechanical properties of polypropylene by in-situ fibrillation

采用原位成纤复合法制备了均聚聚丙烯(PP-H)/聚对苯二甲酸乙二酯(PET)原位成纤复合材料,研究了PET原位微纤化对PP-H力学性能的影响。实验采用的设计工艺可实现PET在PP-H基体中原位微纤化;原位生成的PET纤维对PP-H力学性能的影响呈各向异性,表现为拉伸及弯曲强度提高,冲击强度下降,改善效果受PET微观形态的影响:增大表观拉伸比和添加少量增容剂有利于形成PET微纤,同时,复合试样内PET的形态也受再加工注塑温度的影响。

The authors prepared homo-polypropylene/polyethylene terephthalate （PP-H/PET） composites through in-situ fibrillation and studied influences of in-situ microfibrillation of PET on the mechanical properties of PP-H. The design technology adopted in the experiment of the present work was available for realizing in-situ microfibrillation of PET in PP-H matrix. The PET micro-fibers formed in-situ had anisotropic impact on PP-H＇s mechanical properties, leading to an enhancement in tensile and flexural strength but a reduction in impact strength of the latter. The improvement effect was affected by the micromorphology of the PET fibers in PP-H/PET composites. Increasing apparent stretching ratio or adding a small amount of compatiblizer was favorable to formation of the PET micro-fibers. In addition, the morphology of the PET micro-fibers in the PP-H/PET composites was dependent on injection molding temperature of the reprocessing.