Synthesis and Characterization of Novel Aromatic Polyamides from 3,4-Bis(4-aminophenyl)-2,5-diphenylthiophene and Aromatic Dicarboxylic Acids

Abstract

A new highly phenylated diamine, 3,4-bis(4-aminophenyl)-2,5-diphenylthiophene, was synthesized in three steps starting from 4′-nitrodeoxybenzoin. New aromatic polyamides containing tetraphenylthiophene unit were prepared by the low temperature solution poly-condensation of this diamine with various aromatic dicarboxylic acid chlorides. These polyamides had inherent viscosities of 0.20—0.35 dl g−1 and were generally soluble in various organic solvents such as N,N-dimethylacetamide, N-methyl-2-pyrrolidone, and dimethyl sulfoxide. The glass transition temperatures of the polyamides ranged from 285 to 327°C, and the 10% weight loss temperatures were observed above 530°C in nitrogen.