Polyimide model compounds

Abstract Pyromellitic dianhydride was reacted with various substituted aryl amines, under conditions similar to those used for polyimide formation. Yields of model imides have been greatly improved over those found in previous studies. The work has shown that the major impurities formed when the reactions were performed in solutions of N,N‐dimethylformamide or N,N‐dimethylacetamide were adducts containing chemically bound solvent residues.