Copolyamide-imides of controlled microstructure. Effect of reaction conditions on regularity and properties

Aromatic polyamide-imides, based on trimellitimide and 4,4′-diphenylmethane and with different degrees of order, have been obtained from symmetric and asymmetric monomers. The polymers have been prepared by two general methods: (1) low temperature solution polycondensation of diamines and carboxylic acid derivatives; and (2) high temperature solution polycondensation of diisocyanates and dicarboxylic acids. High field ¹H-NMR has been used to elucidate the chemical structures of monomers and polymers and to estimate quantitatively the degree of order and the distribution of head-to-head, tail-to-tail (amide-amide, imide-imide) and head-to-tail (amide-imide) units. The influences of microstructure and other molecular features on some properties of the polymers have also been investigated.