复合溶剂体系合成聚对苯二甲酰对苯二胺树脂的工艺

Method of Preparing Poly p-Pphenylene Terephthalamide Phenylenediamine in Mixed Solution

介绍了在N,N-二甲基乙酰胺(DMAC)-N-甲基吡咯烷酮(NMP)-氯化锂(LiCl)-吡啶(Py)溶剂体系中使用低温溶液缩聚法合成聚对苯二甲酰对苯二胺(PPTA)树脂的工艺。结果表明:单体的浓度为0.26-0.28mol/L,n(TPC)∶n(PPD)在1.024-1.030,复合溶剂(DMAC-NMP)中NMP体积分数为6%,LiCl用量(占总溶剂的质量分数)为2.6%-2.8%,吡啶(Py)用量(占总溶剂的质量分数)为6.20%-6.68%时可获得聚合物比浓对数粘度ηinh为4.7-4.9的PPTA树脂。相对于传统工艺,该工艺增加了反应速率,降低了对溶剂纯度的要求,有利于制取更高分子质量的PPTA树脂。

The conditions of preparing the PPTA resin in solvent system were studied, including N, N-- dimethyl acetamide, N--methyl pyrrolidone, lithium chloride and pyridine under low temperature. When the monomer concentration is 0. 26--0. 28mol/L, the monomer molar ration is 1. 024-1. 030, the volume fraction of NMP in mixed solvent is 6 %, the amount of LiCl is 2.6 %-- 2.8 % and the amount of Py is 0.7 -0.8mol/L, the viscosity of PPTA can reach 4.7--4.9. Compared with traditional process, the process increases the reaction rate and reduces demand on the solvent purity which is conductive to higher molecular weight of the PPTA.