PREPARATION OF POLY(AMIDE-IMIDE)S BY DIRECT POLYCONDENSATION WITH TRIPHENYL PHOSPHITE .4. ALIPHATIC-AROMATIC POLY(AMIDE-IMIDE)S BASED ON N,N'-BIS(OMEGA-CARBOXYALKYL)PYROMELLITIMIDES

Four diimide‐diacids 3a‐d were synthesized from pyromellitic dianhydride and amino acids of the formula HOOC  (CH2)m  NH2, with m = 1, 3, 5, 10. These diacids were condensed directly with various aromatic diamines using triphenyl phosphite in N‐methyl‐2‐pyrrolidone (NMP)–pyridine solution in the presence of calcium chloride. The resulting poly(amide‐imide)s have an aliphatic‐aromatic structure and the relation between the general properties and the amount of the aliphatic part in the repeat unit was studied. IR spectroscopy, elemental analysis, and inherent viscosity measurements were used for the characterization. Studies of solubility, DSC traces, thermal stability, and crystallinity were also made. Copyright © 1990 John Wiley & Sons, Inc.