New poly(amide‐imide)s synthesis, 16. Preparation and properties of poly(amide‐imide)s derived from 3,3‐bis[4‐(4‐aminophenoxy) phenyl]phthalide and various bis(trimellitimide)s

Abstract

AbstractA series of novel bis(phenoxy)phthalide‐containing poly(amide‐imide)s 3 were synthesized via direct polycondensation of 3,3‐bis[4‐(4‐aminophenoxy)phenyl]phthalide (BAPP) with various aromatic bis(trimellitimide)s 2 in N‐methyl‐2‐pyrrolidone (NMP) using triphenyl phosphite and pyridine as condensing agents. Poly(amide‐imide)s 3 having inherent viscosities up to 1,68 dL/g were obtained in quantitative yields. Most of the resulting polymers showed an amorphous nature and were readily soluble in polar solvents such as NMP and N,N‐dimethylacetamide. All the soluble poly(amide‐imide)s afforded transparent, flexible, and tough films. The glass transition temperatures of these polymers were in the range of 237–292°C and the 10% weight loss temperatures were above 500°C in nitrogen. The properties of poly(amide‐imide)s 3 were compared with those of the corresponding isomeric poly(amide‐imide)s 3′ prepared from 3,3‐[4‐(4‐trimellitimido‐phenoxy)phenyl]‐phthalide and various aromatic diamines.