β晶相聚丙烯纺丝工艺的研究

本文研究了三种不同β晶成核剂的聚丙烯切片的纺丝工艺条件与初生纤维中结晶结构的关系。研究表明,制得的初生纤维中的β晶含量主要取决于含β成核剂聚丙烯的结晶速率和纺丝成形中的冷却速率。含β成核剂E3B聚丙烯的结晶速率最大,纺制的初生纤维β晶含量最高;纺丝成形中的冷却速率愈高,初生纤维中的β晶含量愈低;在一定的温度范围内,纺丝温度对初生纤维中β晶相对含量影响甚微;纺丝冷却条件和纤维束的集束状况对β晶含量有明显的影响;β晶的晶粒尺寸与β晶含量相对应,而初生纤维中的结晶度多在55％左右,受纺丝工艺参数的影响甚小。

STUDY ON THE SPINNING TECHNOLOGY OF β-CRYSTALLINE FORM ISOTACTIC POLYPROPYLENE FIBER

The relation of technological conditions in spinning of β-crystalline form IPP fibers made from 3 different kinds of β-nuclear agents with crystal structures in as-spun fibers is studied. The results show that the relative content of β-form in as-spun fibers depends to a large extent on the crystallization rate of IPP contains β-nuclear agents and the cooling speed in spinning. IPP contains E3B has the highest crystallization rate and so is the β-form content in as-spun fiber, which is decreased with increasing cooling speed. Spinning temperature has little effect on the relative content of β-form (K. value) in as-spun fibers within a certain temperature range while the condition of cooling and collecting of multlfilament have significant effect on it. The higher the content of β-form in as-spun fiber, the bigger the crystallite size. The spinning technological parameters have littla effect on crystallinity which is about 50-60% in as-spun fiber.