SynopsisThe polymerization of 4chloroformylphthalic anhydride with 4,4'-diaminodiphenyl ether was investigated under a variety of reaction conditions. Both interfacial and solution techniques were used, with the latter method yielding the highest molecular weight polymer. Synthesis of high molecular weight polyamideimides requires the w of pure monomers, exclusion of moisture, and proper stoichiometry. Molecular weight control can be achieved by the addition of either aniline or phthalic anhydride.Heating of the resin solution for 1 hr at temperatures >_50°C results in a large decrease in inherent viscosity as well as in the polymer properties. Tertiary amines such as triethylsmine, when added to the precursor solution, markedly induence the viscosity of the resin.