SYNTHESIS AND PROPERTIES OF AROMATIC POLYAMIDES WITH OLIGOBENZAMIDE PENDENT GROUPS .1. POLY-5-(4-BENZOYLAMINO-1-BENZOYLAMINO)ISOPHTHALAMIDES

series of polyisophthalamides having pendent oligomeric benzamide groups were prepared by the Yamazaki reaction from common aromatic diamines and 5-(4-benzoylamino-1-benzoylamino)isophthalic acid. The latter was synthesized from 5-aminoisophthalic acid in a three-step synthesis by successive incorporation of benzamido groups. The new polymers were characterized by NMR, DSC, TGA, and WAXD and the properties were compared to those of corresponding unsubstituted polyisophthalamides. All of the polymers were essentially amorphous and their T(g)s were about 20 degrees C higher than the reference polymers. Initial thermal decomposition temperatures ranged from 375 to 420 degrees C. All of the polymers were soluble in aprotic polar solvents without added salts. Properties of particular note were: the water uptake, which was particularly high, ranging from 7.5 to 18.2%, and the temporary insolubilization in concentrated sulfuric acid of films of the polymers heated for a short time to greater than or equal to 200 degrees C. (C) 1995 John Wiley & Sons, Inc.