聚丙烯/茂金属线形低密度聚乙烯的熔融行为和等温结晶动力学  

Melting Behavior and Isothermal Crystallization Kinetics of PP/m-PE-LLD Blends

作　　者：秦江雷[1] 高俊刚[1] 郑艳菊[1] 李志庭[1] 

机构地区：[1]河北大学化学与环境科学学院,河北保定071002

出　　处：《中国塑料》2007年第10期17-21,共5页China Plastics

基　　金：河北大学科研基金

摘　　要：用示差扫描量热仪测定了共聚聚丙烯(PP)/茂金属线形低密度聚乙烯(m-PE-LLD)共混体系的熔融和等温结晶动力学。结果发现,m-PE-LLD 和 PP 主体中 PE 链段之间存在相互作用。用 Avrami 方程对共混体系的等温结晶动力学进行了研究,m-PE-LLD 的加入对 PP 的结晶动力学参数影响不大,说明 m-PE-LLD 的加入没有起到异相成核作用,而是使 PP 的晶体生长更加完整。由于两者的相容性,m-PE-LLD 的加入明显降低了结晶温度下的过冷度,而使整体结晶速率有所下降。用 Friedman 方程计算了体系的结晶活化能,发现 m-PE-LLD 的加入提高了结晶活化能。同时还用 Hoffman-Lauritzen 理论计算了体系成核参数 K_g。The melting and crystallization behaviors and isothermal crystallization kinetics of polypropylene（PP）/metallocene-catalyzed linear low-density polyethylene（m-PE-LLD） blends were studied using differential scanning calorimetry（DSC）. It showed that PP and m-PE-LLD are partially miscible. The isothermal crystallization kinetics of the blends could be well described with the Avrarni equation. The crystallization mechanism of PP was almost not affected by the inclusion of m-PE-LLD. Values of Avra- mi exponent indicated the crystallization nucleation was heterogeneous, the growth of spherulites was nearly three-dimensional. By addition of m-PE-LLD, both crystallization rate and crystallization temperature of PP were decreased. The crystallization activation energy was estimated by Friedman equation, it increased in a little by addition of a small amount of m-PE-LLD, but remained no change with further increasing content of m-PE-LLD. The nucleation constant Kg was determined using the Hoffman-Lauritzen equation.

关 键 词：聚丙烯 茂金属线形低密度聚乙烯 熔融行为 等温结晶动力学 活化能 

分 类 号：TQ320.1[化学工程—合成树脂塑料工业]