PE-UHMW分子量对PE-HD/PE-UHMW复合材料形态及性能影响  

The Effect of PE-UHMW Molecular Weight on the Morphology and Properties of PE-HD/PE-UHMW Composites

作　　者：周飞[1] 张岩[2] 何雪莲[2] Zhou Fei;Zhang Yan;He Xuelian(SINOPEC Shanghai Petrochemical Company Limited,Shanghai 200540,China;China Shanghai Key Laboratory of Multiphase Material Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China)

机构地区：[1]中国石化上海石油化工股份有限公司,上海200540 [2]华东理工大学多相结构材料化学工程重点实验室,上海200237

出　　处：《工程塑料应用》2020年第7期1-7,共7页Engineering Plastics Application

基　　金：国家自然科学基金面上项目(51573048)。

摘　　要：将超高分子量聚乙烯(PE-UHMW)与高密度聚乙烯(PE-HD)分子量之比分别设为4.6∶1,12.5∶1,25∶1和50∶1,在溶液中实现分子链均匀混合,再借助超声辅助挤出设备熔融共混制备PE-HD/PE-UHMW复合材料,研究了PE-UHMW分子量对复合材料力学性能的影响机制。结果发现由于PE-UHMW的分子链很长,其分子之间的缠结密度增大,分子间具有较大的摩擦力,分子链驰豫时间变长,中心纤维核增长变多,因此,随着PE-UHMW分子量的增大,复合材料体系越能够在成型过程中形成更丰富的串晶结构,而且在拉伸破坏过程中,更容易发生球晶的破碎重结晶,形成单一取向的串晶结构,因此,复合材料的屈服强度和断裂强度均增大;且PE-UHMW对PE-HD的分子链约束性更强,弹性更好,导致其断裂伸长率较大。The molecular weight ratios of PE-UHMW and PE-HD were designed to be 4.6:1,12.5:1,25:1 and 50:1 respectively.The molecular chains were uniformly mixed in the solution,and then the PE-HD/PE-UHMW composite was prepared by melt blending with the aid of ultrasonic assisted extrusion equipment.The influence mechanism of the molecular weight of PE-UHMW on the mechanical properties of the composite was studied.The results show that the molecular chain of PE-UHMW is very long,the entanglement density between the molecules increases,the friction force between the molecules increases,the relaxation time of the molecular chain becomes longer,and the growth of shish nucleus becomes more.Thus,with the increase of molecular weight of PE-UHMW,the composite system can form more abundant shish-kebab structure in the forming process,and spherulites are more likely to occur in the tensile failure process.As a result,the yield strength and break strength of the composite increase gradually,and PE-UHMW is more restrictive and elastic to the molecular chain of PE-HD,which results is in a larger elongation at break.

关 键 词：聚乙烯 流变 结晶动力学 拉伸流场 串晶 

分 类 号：TQ[化学工程]