摘要
在熔体拉伸的高密度聚乙烯薄膜中,含有高取向的片晶结构。分子链轴(c 轴)平行于拉伸方向,b 轴在薄膜平面内,片晶生长方向垂直于拉伸方向。加入少量超高分子量(约2×10~6)组分,导致纤维晶生成。纤维晶平行于拉伸方向,穿过几个片晶区,其长度在微米范围。纤维晶由伸展链分子构成,超高分子量组分是其成核中心。超高分子量组分松弛时间长.在熔体拉伸过程中有利于链伸展。
The melt-drawn films of high density polyethylene(HDPE)con-sist of highly oriented lamellar structure with their chain c axis parallel todrawing direction and b axis in the films plane.The lamellar growing directionis vertical to the drawing direction.Adding small amount of ultra-high molecular weight component(about 1%)into HDPE results in formation of fibrous crystals,which are parallel to thedrawing direction.The length of the fibrous crystals is in the order of micron.The fibrous crystals consist of extended chains,while the ultra-high molecularweight component forms the cores of the fibrous crystals.The presence of ultra-high molecular weight component in melt-drawnHDPE films results in the increase of tensile modulus and strength considerably,
基金
国家自然科学基金
9287006
关键词
聚乙烯
薄膜
取向结晶
结构
high density polyethylene orientation crystallization
morphology structure
mechanical property
