The present necessity to use heat-resistant materials in electronics justifies the scientific interest in different heterocyclic polymers. This paper is especially concerned with the preparation of novel heat-resistant polyimides having bisbenzimidazole moieties in the main chain and their applications as dielectric films. A soluble copolyimide was prepared by a two- step synthesis from aromatic dianhydrides and aromatic diamines. The bisbenzimidazole ...