Effect of Nitrile Groups and of Flexible Linkages on the Properties of Poly(Ether Imide) Films

Aromatic poly(ether imide)s were synthesized using two diamines containing one or two nitrile groups and ether linkages, with dianhydrides exhibiting different degrees of flexibility. The effect of nitrile groups and of ether linkages, inserted into polymer chains, was correlated with their physical properties. The polymers have a very good solubility and high thermal stability. Poly(ether imide)s had the initial decomposition temperature in the range of 400–520°C and glass transition temperatures in the domain of 169–232°C, depending on the rigidity of the chain. The electrical properties and molecular relaxations were evaluated, taking into account the presence of polar nitrile group.