STUDIES ON THE REGULAR COPOLYMERS OF POLY (1, 4-PHENYLENETEREPHTHALAMIDE)

摘要

Two types of the regular copolymer of poly （1, 4-phenyleneterephthalamide） were synthesized by the low temperature solution polycondensation in NMP-CaCl2 solvent system, using the piperazine or 2,5-dimethylpiperazine as the third components introduced in the main chain of poly （1, 4-phenyleneterephthalamide）. The properties of copolymers were characterized by IR, SEM, X-RAY diffraction, polarizing microscopy, TGA and solubilities.Experimental results showed that the copolymers had good solubility and thermal stability, the concentrated sulfuric acid （～98% ） solution of regular PPTA copolymers had liquid crystalline proper-