原位聚合改性滑石粉/PP复合材料的微观结构和力学性能

MICRO-STRUCTURE AND MECHANICAL PROPERTIES OF IN-SITU POLYMERIZATION-MODIFIED TALC/PP COMPOSITES

通过熔融共混制备了丙烯酸丁酯(BA)原位聚合改性滑石粉/聚丙烯(PP)复合材料。研究了原位聚合改性对滑石粉/PP复合材料形貌、晶型结构、结晶熔融行为和力学性能的影响。结果表明,PP和滑石粉在熔融共混过程中,剪切力的作用使层叠的滑石粉剥离成不同厚度的片层,BA原位聚合改性改善了滑石粉与PP之间的界面粘结,有利于滑石粉在PP基体中的剥离;滑石粉的原位聚合改性,促进了β-晶型PP的生成,提高了滑石粉/PP复合材料中PP相的熔点、结晶速率和结晶度,降低了PP相的结晶温度。同时显著提高了滑石粉/PP复合材料的冲击强度,且存在一最佳的BA用量。

Talc/polypropylene （PP） composites were prepared by melt blending and injection molding, in which talc was firstly modified by in-situ polymerization of butyl acrylate （BA）. The effects of in-situ polymerization modification on the micro-structure, crystal structure, thermal behavior and mechanical properties of the composites were systematically investigated. The results showed that talc layers are delaminated to platelets with multi-scale in thickness in composites by high shearing force during the processing. The in-situ polymerization of BA enhanced the interracial adhesion between talc and PP, which was benefit to the delamination of talc. On the other hand, the modification of talc was in favor of inducing the formation of β-form PP crystals. The PBA-modified talc increases the melting temperature, crystallization rate and degree of crystallinity, while decreased the crystallization temperature of PP phase in composites. The PBA coating on talc surface improves obviously the Izod impact strength of talc/PP composites, and there existed a critical content of BA.