Study of the stability of some imide type polymers in alkaline medium

Abstract The stability of some polyamide‐imides in alkaline medium was compared to the structurally related amide and imide homologs. The following order of stability in alkaline medium was established: aromatic polyamide > polyamide‐imide > polyimide. This order results from the different stabilities of the poly(amic acids) formed as a result of the hydrolysis. The presence of carboxylic substituents in the ortho position to the amide groups of the poly(amic acids) determines the different stability of polymers.