链分布和平均链长对半晶态聚乙烯结构及力学性能的影响  

Effect of Chain Distribution and Average Chain Length on the Structure and Mechanical Properties of Semi-crystalline Polyethylene

作　　者：刘龙攀 陈占春[1,2] 王飞[1,2] 李红[1,2] 李星宇 Liu Longpan;Chen Zhanchun;Wang Fei;Li Hong;Li Xingyu(School of Machinary Engineering,Taiyuan University of Technology,Taiyuan 030024China;Shanxi Key Laboratory of Fully Mechanized Coal Mining Equipment,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]太原理工大学、机械工程学院,山西太原030024 [2]太原理工大学、煤矿综采装备山西省重点实验室,山西太原030024

出　　处：《塑料科技》2018年第12期24-29,共6页Plastics Science and Technology

基　　金：国家青年科学基金项目(51303123)

摘　　要：采用分子动力学方法,建立粗粒化聚乙烯模型,设置不同链分布和不同平均链长的混合体系,对它们分别进行结晶和拉伸模拟,分析链的分布和平均链长对半晶态聚乙烯结构及力学性能的影响。由不同链分布体系的结晶结果可知,混链体系中长短链的结晶速率不同,链长越长越易结晶,但因受到短链的制约作用而变缓;其拉伸结果显示混链体系的屈服应力更大。对比不同平均链长的混链体系的结晶结果,观察到链长越短,结晶时间越长,得到的半晶体结晶度越高;由拉伸结果可知,短链体系所需应力最小,最终取向度最高。Molecular dynamics (MD) method was used to establish the coarse grained polyethylene (PE) model. Mixed systems with different chain distributions and different average chain lengths were set up to simulate their crystallization and tensile properties respectively. The effects of chain distribution and average chain length on the structure and mechanical properties of semicrystalline PE were analyzed. From the results of crystallization of different chain distribution systems, it can be seen that the longer the chain length is, the easier the crystallization is, but the longer the chain length is, the slower the crystallization is. The tensile results show that the yield stress of the mixed chain system is greater. Comparing the crystallization results of mixed chains with diff erent average chain lengths, it was observed that the shorter the chain length, the longer the crystallization time, and the higher the crystallinity of the semi-crystals. The results show that the short chain system has the lowest stress and the ultimate orientation is the highest.

关 键 词：半晶态聚乙烯 分子动力学 粗粒化模型 混合体系 结晶 拉伸 

分 类 号：TQ325.12[化学工程—合成树脂塑料工业]