传统挤出聚乙烯管的多层次结构及应用中的薄弱点  

Hierarchical Structure of Polyethylene Pipe Prepared via Convention Extrusion and Weak Structures in Application

作　　者：华正坤[1] 聂敏[1] 王琪[1] 

机构地区：[1]高分子材料工程国家重点实验室四川大学高分子研究所,四川成都610065

出　　处：《塑料》2015年第1期77-79,共3页Plastics

基　　金：国家自然科学基金科学仪器基础研究专项(51127003)

摘　　要：利用多种表征方法,系统地研究了3种管径PE管的多层次结构。结果表明:聚合物熔体在挤管过程中受到轴向挤出/牵引作用,分子链易沿轴向取向,而沿厚度方向存在的温度梯度也使片晶沿径向取向排列。对小口径PE管而言,管壁厚度较薄,这2种取向更加明显。XRD和DSC实验表明:管径变化对PE管晶体结构影响不大,但由于外壁快速喷淋冷却,内壁冷却速度较慢,形成的片晶厚度较大,tie分子链含量较低。Hierarchical structures of polyethylene pipes with three diameters prepared via convention extrusion were investigated systematically by various characterization methods. The experimental results showed that the polymer melts were subjected to axial extrusion / traction effects to induce axial orientation of the polymer chains while the temperature gradient along the thickness direction also promoted the lamellae to orient along the radial direction during the extrusion process. As for PE pipes with small diameter, these two orientations were more obvious owing to the thinner wall thickness. XRD and DSC experiments showed that diameter of PE pipe had little effect on the crystal structure, but due to the rapid spray cooling on the outer wall, the cooling rate of the inner wall was slow, so the formed lamellae were thicker and the content of tie molecules was 10W.

关 键 词：聚乙烯管 挤出 取向 结晶 多层次结构 

分 类 号：TQ325.12[化学工程—合成树脂塑料工业]