SYNTHESIS OF SULFONE-CONTAINING POLYAMIDES BY DIRECT POLYCONDENSATION WITH TRIPHENYL PHOSPHITE

Several sulfone‐containing polyamides were prepared by the direct polycondensation reaction of 4,4′‐dicarboxydiphenyl sulfone (DCDPS) with various aromatic diamines by means of triphenyl phosphite in NMP‐pyridine solution containing 4 wt % LiCl. DCDPS was synthesized in two steps by the preparation of 4,4′‐dimethyldiphenyl sulfone (DMDPS) from toluene and chlorosulfonic acid and subsequent oxidation with an alkaline solution of potassium permanganate. The polyamides were obtained in 85–100% yield and had inherent viscosities in the range 0.42–1.65 dL/g. Their solubility, crystallinity, and thermal properties are also discussed. Copyright © 1990 John Wiley & Sons, Inc.