超高相对分子质量PPTA树脂及其高模量芳纶的研究

对高相对分子质量聚对苯二甲酰对苯二胺(PPTA)树脂进行了表征,开展了添加超高相对分子质量PPTA树脂与普通相对分子质量PPTA树脂共混进行液晶纺丝得到高强度和高模量芳纶的结构表征与性能试验,同时对芳纶的力学性能与其PPTA树脂相对分子质量的关系进行了研究。结果表明,芳纶的力学性能与其PPTA聚合体的相对分子质量紧密相关,如果PPTA树脂的相对分子质量不够高,加上液晶纺丝和高模量热处理过程分子链的进一步降解,高模量芳纶的制备就无法实现。在系统研究PPTA聚合反应规律,特别是聚合诱导相互转变规律及其影响因素研究基础上,通过调控连续聚合的反应条件,在1 000 t/a连续聚合生产线上制备出比浓对数粘度高达9.2 dl/g的超高相对分子质量PPTA树脂;用超高相对分子质量PPTA树脂与通用级PPTA树脂(比浓对数粘度6.8 dl/g)混合进行纺丝,制备出高强度的芳纶,并进一步热处理得到高强度和高模量的芳纶。

Structure and properties of ultra high molecular weight of PPTA resin and its high modulus fiber

High molecular weight （poly para-phenylene terephthalamide） PPTA resin were characterized.The structure and mechanical property of high tensile strength and modulus fibers have been investigated.These fibers have been spun from liquid crystalline solutions by means of a dry-jet wet spinning process with ultra-high molecular weight of PPTA resin and general PPTA resin.And we studied the relationship between the mechanical property of fibers and molecular weight of PPTA resin.The results show that the tensile strength of PPTA fiber is depend on the molecular weight of the polymer.If the molecular weight of PPTA resin is not enough high and with the degradation by the process of spinning and heat treatment,it is hard to make high modulus fibers.On the base of the research of the polymerization induced phase transfer,we prepared the ultra-high molecular weight PPTA resin （logarithmic viscosity of 9.2 dl/g） in continuous polymerization production line of 1000 tons a year by controlling the reactions conditions.Ultra-high molecular weight of PPTA resin and general level of PPTA resin （logarithmic viscosity of 6.8 dl/g） were mixed to spin and get the high tensile strength fiber,further thermal drawing process was used to obtain obtain aramid fibers with high tensile strength and high modulus.