【摘要】 用超高分子量聚乙烯(UHMWPE)制成的凝胶初生纤维在合适的条件下,进行高达192倍的拉伸。得到强度和模量分别为4.4 GPa和210 GPa的聚乙烯纤维。借助于广角X-射线衍射法(WAXD)、差示扫描量热法(DSC)等手段,对纤维在拉伸过程中的结晶度、取向度、晶胞参数、拉伸应力、残留溶剂含量及纤维强度、模量作了测试。据此,作者认为:UHMWPE纤维在热拉伸过程中,结构的发展和形成可以粗略地分为三个阶段:第一阶段,凝胶纤维中的溶剂被挤出,大分子发生取向;第二阶段,折叠链片晶开始被拉直,经过这个阶段,晶体密度上升约10％,熔点上升4～6℃;经第三个阶段后,晶体密度进一步上升10％,熔点再次上升3℃。更多还原

【Abstract】 In this paper, ultra-high molecular weight polyethyiene (UHMWPE) as-spun gel fibers were drawn up to the ratio of 192 under suitable condition, thus final product with tenacity 4.4 GPa and modulus 210 GPa was obtained. By means of WAXD and DSC et al. crystallinity, degree of orientation, unit cell parameters, tensile force of drawing, content of solvent, tenacity and modulus of the fibers were measured. The authors suggest that: There are three stages in the development of fiber structure during hot-drawing process. The first stage is the removal of solvent from the gel fiber and the orientation of molecular chains. The second stage was the extension of folded lamellar crystals. The crystal density increased by 10% after the second stage and the melting point (T_m) increased by 4～6℃. The crystal density increased by further 10% and T 3℃ after the third stage.更多还原