高熔体强度聚丙烯/嵌段共聚聚丙烯共混体系的结晶行为研究

Crystallization Behavior of High Melt Strength Polypropylene/Block Polypropylene Blends

通过熔融共混法制备了高熔体强度聚丙烯/嵌段共聚聚丙烯(HMSPP/PP-B)共混体系,利用差示扫描量热仪研究了HMSPP/PP-B共混体系的结晶熔融行为和非等温结晶动力学;用偏光显微镜对该共混体系的结晶形态进行了表征。结果表明,随着共混体系中PP-B含量的变化,其结晶熔融行为会发生不同的变化,PP-B能够提高共混体系的结晶温度和熔融温度,并且显著提高HMSPP/PP-B共混体系的球晶数量,降低球晶尺寸;同时会提高共混体系的结晶速率。

High melt strength/block polypropylene（HMSPP/PP-B） blends were prepared by a twin-screw extruder. The non-isothermal crystallization behavior of the blends was studied using differential scanning calorimetry by various cooling rates and was analyzed with Jezionry method. The morphology of spherulites of blends were observed by POM. It was found that the melt and crystallization temperature of blends increased with the increasing of PP-B. Besides, PP-B could change the crystallization process of blends leading to smaller spherulites size and more spherulites amount.