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

series of polyisophthalamides having pendent oligomeric benzamide grou ps were prepared by the Yamazaki reaction from common aromatic diamine s and 5-(4-benzoylamino-1-benzoylamino)isophthalic acid. The latter wa s synthesized from 5-aminoisophthalic acid in a three-step synthesis b y successive incorporation of benzamido groups. The new polymers were characterized by NMR, DSC, TGA, and WAXD and the properties were compa red to those of corresponding unsubstituted polyisophthalamides. All o f the polymers were essentially amorphous and their T(g)s were about 2 0 degrees C higher than the reference polymers. Initial thermal decomp osition temperatures ranged from 375 to 420 degrees C. All of the poly mers were soluble in aprotic polar solvents without added salts. Prope rties of particular note were: the water uptake, which was particularl y high, ranging from 7.5 to 18.2%, and the temporary insolubilization in concentrated sulfuric acid of films of the polymers heated for a sh ort time to greater than or equal to 200 degrees C. (C) 1995 John Wile y & Sons, Inc.