Synthesis and Characterization of Polyimide from 4,4’-Diamino diphenyl ether having Substituents at 2,2’-position

Aromatic polyimides having phenyl groups and trifluoromethyl groups at 2,2’-position of the diphenyl ether moieties have been prepared from bis(4-amino-2-biphenyl)ether (1) and bis(4-amino-2-trifluoromethylphenyl)ether (2), respectively and various tetracarboxylic dianhydrides by the conventional two-step procedure. The substituents at 2,2’-position of the diphenyl ether had a great influence on the properties of polyimides. In this paper, aromatic polyimises having only one phenyl group at 2,2’-position of the diphenyl ether moieties are prepared from 4,4’-diamino-2-phenyldiphenylether (3), and the properties are compared with those of the polyimides from 1 and 2.