摘要
采用低温溶液缩聚法将对苯二甲酰氯(TPC)和对苯二胺(PPD)在NMP-CaCl_2溶剂体系中进行缩聚反应,制备了较高分子质量的聚对苯二甲酰对苯二胺(PPTA)树脂。研究了分子质量与反应时间的关系,考察了初始单体浓度、摩尔配比、起始反应温度、反应时间等影响缩聚反应的因素,获得了较优的聚合条件:初始单体浓度为0.35～0.4mol/L,对苯二甲酰氯和对苯二胺的摩尔配比为1.009～1.012,起始反应温度为-15～5℃,反应时间为35～60min。发现搅拌转速对于聚合分子质量的影响主要体现在低转速范围,当转速超过某一临界值时,转速对PPTA聚合分子质量几乎没有影响。
Poly（p-phenylene terephthalamide） （PPTA） with relative high weight average molecular weight was synthesized by low-temperature polycondensation of p-phenylene diamine （PPD） and terephthaloyl chloride （TPC） in mixed solvent N-methyl pyrrolidone （NMP） and Calcium Chloride （CaCI2）. The main factors of influencing the low temperature solution polycondensation such as initial monomer concentration, TPC/PPD molar ratio, initial reaction temperature, retation speed and the variation of weight average molecular weight with time were studied in detail. It showed that these factors have significant effects on the weight average molecular weight, and the highest molecular weight can be obtained at range of 0.35- 0.4mol/L, TPC/PPD molar ratio range of 1.009- 1.012 and initial temperature range of - 15 -5℃. Meanwhile, molecular weight of polymer increased rapidly with time in the early stage of polymerization process and then hardly changed after about 60 min. In addition, once rotation speed exceeds some critical value, the increase of weight average molecular weight has hardly been observed.
出处
《合成技术及应用》
2008年第4期1-4,共4页
Synthetic Technology & Application
关键词
聚对苯二甲酰对苯二胺
低温溶液缩聚
合成
poly（p-phenylene terephthalamide）
low-temperature solution polycondensation
synthesis
