METHOD OF SYNTHESIS OF POLY-PARA-PHENYLENETEREPHTHALAMIDE AND ITS COPOLYMERS Russian patent published in 2001 - IPC

FIELD: organic chemistry and technology. SUBSTANCE: invention describes method of synthesis of poly-p- -phenyleneterephthalamide and its copolymers by dissolving p-phenylenediamine and its mixture with other diamines in medium of amide-salt solvent, cooling diamine solution to 0-10 C and addition of dicarboxylic acid dichloroanhydride to solution at stirring. Dicarboxylic acid dichloroanhydride is added to diamine solution by fractions in each 5-15 min. The first portion is 11-33.3% of amount of p-phenylenediamine to be dissolved and taken in moles and the next each portion exceeds the previous one by 2-fold; the latter portion is the difference between amount of dissolved diamines and dicarboxylic acid dichloroanhydride taken as g-mole. Method provides synthesis of the light colorless polymer of p= phenyleneterephthalamide with decreased ash content. EFFECT: improved method of synthesis, enhanced quality of end product. 2 cl, 1 tbl