无规共聚聚丙烯的非等温结晶动力学研究

Kinetics study on non-isothermal crystallization of polypropylene random copolymer

研究了无规共聚聚丙烯(PPR)在不同降温速率下的非等温结晶行为,采用Jeziorny法、Ozawa法和莫志深法等模型分析了PPR的非等温结晶动力学。模拟结果表明,加入α成核剂的PPR力学性能优异,具有更高的结晶温度和结晶度;Jeziorny法和莫志深法的分析结果表明,加入α成核剂的PPR表现出更快的结晶速率,且两种不同的α成核剂对PPR结晶性能的改善效果相近;利用Kissinger公式计算PPR的非等温结晶活化能的结果表明,α成核剂改性的PPR具有较高的非等温结晶活化能;加入α成核剂可使PPR形成更小的球晶。

The non-isothermal crystallization behaviors of the polypropylene random copolymer(PPR)at different cooling rates were investigated.Various kinetic models,namely,the Jeziorny method,the Ozawa method and the Mo Zhishen method were employed to analyze the non-isothermal crystallization kinetics of the PPR samples.The PPR samples withαnucleating agents show better mechanical properties and higher crystallization temperature and crystallinity.The analysis results of the Jeziorny method and Mo Zhishen method indicate that the crystallization rate of the PPR samples with differentαnucleating agents are faster than that of the pure PPR.Besides,two differentαnucleating agents have similar effects on PPR crystallization.The estimation results by Kissinger formula show that PPR modified withαnucleating agents has high activation energy for non-isothermal crystallization.The addition ofαnucleating agent can make PPR form smaller spherulites.