Synonyms: [5,5'-Biisobenzofuran]-1,1',3,3'-tetrone, polymer with 4,4'-oxybis [benzenamine];[5,5'-biisobenzofuran]-1,1',3,3'-tetrone, polymer with 4,4'-oxybis[benzenamine];[5,5'-biisobenzofuran]-1,1',3,3'-tetrone, polymer with4,4'-oxybis[benzenamine];4,4'-Diaminodiphenyl ether, 3,3',4,4'-biphenyltetracarboxylic dianhydride copolymer