화학공학소재연구정보센터
Journal of Polymer Science Part A: Polymer Chemistry, Vol.36, No.12, 1987-1994, 1998
Synthesis and properties of new soluble aromatic polybenzoxazoles from 4,4 '-diamino-3,3 '-dihydroxytriphenylamines and aromatic dicarboxylic acids
Two new triphenylamine-based bis(o-aminophenol) monomers, 4,4'-diamino-3,3'-dihydroxytriphenylamines, were successfully synthesized by the cesium fluoride-mediated condensation of 2-(benzyloxy)-4-fluoronitrobenzene with aniline derivatives, followed by simultaneous deprotection and reduction. Aromatic polybenzoxazoles having inherent viscosities of 0.58-1.05 dL/g were obtained by the low-temperature solution polycondensation of the bis(aminophenol)s with various aromatic dicarboxylic acid chlorides and the subsequent thermal cyclodehydration of the resultant poly(hydroxyamide)s. All the polybenzoxazoles were amorphous, and most of them were soluble in organic solvents such as m-cresol and o-chlorophenol. Flexible and tough films of polybenzoxazoles could be cast from the DMAc solutions of some aromatic poly( hydroxyamide) s, followed by thermal cyclodehydration. The glass transition temperatures and 10% weight loss temperatures of the polybenzoxazoles under nitrogen were in the range of 262-327 and 610-640 degrees C, respectively.