Compared properties of aromatic polyisophthalamides containing 5-(4-acetoxy-benzamido) pendent groups

A series of aromatic polyamides containing 5-(4-acetoxy-benzamido) pendent groups have been synthesized and their properties have been characterized a nd compared with those of related polyamides. The polyamides have weight- a nd number-average molecular weights in the range of 36,680-65,700 and 12,68 5-35,490, respectively, and polydispersities in the range of 1.82-3.66. The se polymers show good thermal stability comparable to traditional aromatic polyisophthalamides, with initial decomposition temperature between 270-320 degreesC and glass transition temperature in the range of 230-270 degreesC . Compared with related polyisophthalamides without any pendent groups, the present polymers show better solubility in certain solvents such as N-meth ylpyrrolidinone and dimethylacetamide and can be cast from solutions into t hin transparent flexible films having dielectric constants in the range of 3.42-4.27. The polymer films display remarkable hydrophilicity, which makes them potential candidates for use as advanced materials in humidity sensor s. (C) 2001 John Wiley & Sons, Inc.