超支化聚合物对聚丙烯等温结晶动力学的影响

The Effect of Hyperbranched Polymer on Isothermal Crystallization Kinetics of Polypropylene

采用示差扫描量热仪(DSC)研究聚合物结晶动力学,讨论了添加5%超支化聚合物对聚丙烯结晶行为的影响,结果表明,少量超支化聚合物可使聚丙烯的结晶速度显著提高,Avrami指数明显增加。偏光显微镜照片显示,超支化聚合物的引入使体系晶核数目急剧增加,球晶的半径明显变小。

The isothermal crystallization kinetics of pure isotactic polypropylene（iPP） and iPP with 5% AB3 hyperbranched polymer（HBP） added were investigated by differential scanning calorimetry（DSC）.During isothermal crystallization,the crystallization rate of the blend was higher than those of iPP remarkably.An increase in the Avrami exponent may be attributed to the fractal structure of hyperbranched polymer.The polarized micrographs of the HBP/PP blend showed the number of effective nuclei increased obviously and the sphereulite size reduced rapidly.