SYNTHESES OF POLYAMIDES AND POLYBENZODIPYRROLEDIONES FROM PSEUDO DIACETYLPHTHALOYL CHLORIDES AND DIAMINES

In the reported experiments, novel diacetylphthalic acis, 2,5-diacetylterephthalic and 4,6-diacetylisophthalic acids, were synthesized starting from pyromellitic dianhydride. These diacids were subsequently converted to the corresponding pseudo diacetylphthaloyl chlorides with aliphatic diamines in a polar aprotic solvent afforded almost quantitatively polyamides having inherent viscosities of 0. 3-0. 7. The solution polymerization was almost completed within 1 hr at room temperature. These polyamides were soluble in acidic solvents like m-cresol. Subsequent cyclodehydration of the polyamides by heating at 200 degree degree C gave insoluble polybenzodipyrrolediones, which underwent weight losses of 10% at around 400 degree C under nitrogen.