Preparation and properties of aromatic polyamides from 2,2′‐bis(p‐aminophenoxy) biphenyl or 2,2′‐bis(p‐aminophenoxy)‐1,1′‐binaphthyl and aromatic dicarboxylic acids

Abstract

Abstract New aromatic diamines having kink and crank structures, 2,2′‐bis( p ‐aminophenoxy)biphenyl and 2,2′‐bis( p ‐aminophenoxy)‐1,1′‐binaphthyl, were synthesized by the reaction of p ‐fluoronitrobenzene with biphenyl‐2,2′‐diol and 2,2′‐dihydroxy‐1,1′‐binaphthyl, respectively, followed by catalytic reduction. Biphenyl‐2,2′‐diyl‐ and 1,1′‐binaphthyl‐2,2′‐diyl‐containing aromatic polyamides having inherent viscosities of 0.44–1.18 and 0.26–0.88 dL/g, respectively, were obtained either by the direct polycondensation or low‐temperature solution polycondensation of the diamines with aromatic dicarboxylic acids (or diacid chlorides). These polymers were readily soluble in a variety of organic solvents including N , N ‐dimethylacetamide (DMAc), N ‐methyl‐2‐pyrrolidone (NMP), dimethyl sulfoxide, m ‐cresol, and pyridine. Transparent, pale yellow, and flexible films of these polymers could be cast from the DMAc or NMP solutions. These aromatic polyamides containing biphenyl and binaphthyl units had glass transition temperatures in the range of 215–255 and 266–303°C, respectively. They began to lose weight at ca. 380°C, with 10% weight loss being recorded at about 470°C in air. © 1993 John Wiley & Sons, Inc.