云母粉对注塑发泡PP/EPDM共混物泡孔结构和力学性能的改善

Improvement of Cellular Structure and Mechanical Properties for Foam Injection Molding PP/EPDM Blend with Mica

采用注塑发泡方法制备了质量比为75/25的聚丙烯/三元乙丙橡胶(PP/EPDM)共混物和质量比为75/25/7.5的PP/EPDM/云母粉复合材料制品,分析了两种制品泡孔结构和结晶性能的差异及其对制品力学性能的影响。结果表明:与共混物发泡制品相比,复合材料发泡制品的拉伸屈服强度、拉伸断裂强度、断裂伸长率和无缺口冲击强度分别提高约5%、48%、206%和22%,并呈现应变硬化现象。复合材料发泡制品的泡孔直径明显较小且分布较均匀,泡孔密度明显较大,结晶度较高,这些是使复合材料发泡制品具有较高力学性能的主要原因。

Foamed polypropylene/ethylene-propylene-diene monomer （PP/EPDM, 75/25, w/w） blend and PP/EPDM/mica composite （75/25/7.5, w/w） were prepared via injection molding. The differ- ence in the cellular structure and crystallization properties of both foamed parts and its effect on their mechanical properties were studied. The results showed that comparing with the foamed blend part, the foamed composite part exhibited an increase of 5% , 48%, 206%, and 22% in tensile yield strength, tensile facture strength, elongation at break and un-notched impact strength peared for the latter part. These results were attributed muc much larger cell density, and higher , respectively. Moreover, strain hardening aph smaller and more uniform cellular diameters, crystallinity of the foamed composite parts.