Synthesis and properties of novel aromatic poly(o-hydroxy amide)s and polybenzoxazoles based on the bis(ether benzoyl chloride)s from hydroquinone and its methyl-, tert-butyl-, and phenyl-substituted derivatives

Four series of poly(o-hydroxy amide)s were prepared by the low-temperature solution polycondensation of the bis(ether benzoyl chloride)s extended from hydroquinone and its methyl-, tert-butyl-, or phenyl-substituted derivativ es with three bis(o-aminophenol)s. Most of the poly(o-hydroxy amide)s displ ayed an amorphous nature, were readily soluble in various polar solvents su ch as N,N-dimethylacetamide (DMAc), and could be solution-cast into flexibl e and tough films. These poly(o-hydroxy amide)s had glass transition temper atures (T-g) in the range of 152-185 degrees C and could be thermally cyclo dehydrated into the corresponding polybenzoxazoles approximately in the reg ion of 200-400 degrees C, as evidenced by the DSC thermograms. The thermall y converted benzoxazole polymers exhibited T(g)s in the range of 215-247 de grees C and did not show significant weight loss before 500 degrees C eithe r in nitrogen or in air. (C) 1999 John Wiley & Sons, Inc. J Polym Sci A: Po lym Chem 37: 2129-2136, 1999.