高密度聚乙烯与其他聚烯烃共混物高取向薄膜结晶结构的电子显微学研究

Electron Microscopic Study of the Crystal Structure of Highly Oriented Films of HDPE/Polyolefin Blends

本文用透射电子显微镜方法研究了高密度聚乙烯(HDPE)与其它聚烯烃[包括线性低密度聚乙烯(LLDPE)、低密度聚乙烯(LDPE)、等规聚丙烯(iPP)、聚丁烯-1(PB-1)等]共混物高取向薄膜的结晶结构,其中聚烯烃组分含量为10%。在共混物熔体拉伸薄膜中,HDPE以高取向的片晶形式存在,片晶的生长方向垂直于拉伸方向。共混物中LLDPE、LDPE与HDPE形成共晶。与HDPE不相容的iPP、PB-1在共混体系中未观察到明显的相区存在。聚烯烃组分的加入,不仅影响HDPE的片晶尺寸,同时影响结构的对称性,即由纯HDPE的非对称“近单晶”结构变为对称的纤维结构。

The crystal structure of highly oriented melt-drawn films of blends of HDPE/Polyolefin(LLDPE,LDPE, iPP,PB-1)=90/10 were investigated by transmission electron microscopy(TEM). The melt-drawn films of HDPE consist of highly oriented lamellar structure,the lamellar growing direction is perpendicular to the drawing direction.The LLDPE,LDPE with HDPE form co-crystallization in highly ori- ented blends.No marked phases of iPP,PB-1 were found in iPP,PB-1 and HDPE blends.The average crystal size(lamellar thickness and width)of HDPE decrease with addition of Polyolefin components,as well as the change of HDPE texture from a single crystal texture to fibre symmetric structure.