Aromatic polyamides with imide pendent groups

Abstract Aromatic polyamides with imide pendent groups were prepared from 4,4′‐diaminodiphenylether and imide‐diacid chlorides by solution polycondensation. Imidediacid chlorides used included the diacid chlorides of 5‐maleimidoisophthalic, 5‐dichloromaleimidoisophthalic, 5‐tetrahydrophthalimidoisophthalic, 5‐chlorendimidoisophthalic, 5‐nadimidoisophthalic, 5‐methylnadimidoisophthalic and 5‐phthalimidoisophthalic acid. The pure aromatic polyamide from 4,4′‐diaminodiphenylether and isophthaloyl chloride was also prepared for comparative reasons. Polyamide‐imides are soluble in polar organic solvents and show good thermal resistance. They are film‐forming and the films have good mechanical properties. Those polyamide‐imides which contain unsaturated carbon‐carbon bonds may be crosslinked by heating to 220°C, giving rise to insoluble materials with improved mechanical resistance.