POLYIMIDES CONTAINING CARBONYL AND ETHER CONNECTING GROUPS

Several new polyimides were prepared from the reaction of four aromatic dianhydrides with four new diamines containing carbonyl and ether connecting groups between the aromatic rings. The diamines were prepared from the reaction of 4-aminophenol with activated aromatic difluoro compounds in the presence of potassium carbonate. Several of these polyimides were shown to be semicrystalline as evidenced by wide angle x-ray diffraction and differential scanning calorimetry. Glass transition temperatures ranged between 192 and 247 degree C and crystalline melt temperatures were observed between 350 and 442 degree C. The polyimide from the reaction of 3,3 prime ,4,4 prime -benzophenonetetracarboxylic acid dianhydride and 1,3-bis(4-aminophenoxy-4 prime -benzoyl)benzene provided a semicrystalline solvent resistant transparent film with high tensile properties and compression molded compact tension specimens with high fracture toughness.