Copolyanhydride‐imides

Various copolyanhydride‐imides have been obtained from diacids containing the preformed imide group by directly reacting of trimellitic anhydride with various aromatic and aliphatic amines. The polymerization process took place in several stages. In the first stage the diacetyl derivatives were obtained from the corresponding diacids by reactions with acetic anhydride. Under special temperature and pressure conditions, polymers were obtained from these derivatives and the chain grew by developing acetic anhydride between contiguous molecules. The polymers obtained are crystalline, have high thermal stability and good electrical properties. Their structures were determined by IR spectroscopy and elementary analysis and the relationships between their properties and the polymer structures were investigated.