复合溶剂体系合成聚对苯二甲酰对苯二胺树脂的工艺

摘要：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。

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

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.