Processable heat resistant polyamides

Aromatic polyamides containing sulpide, sulphone and ketone groups were prepared by the direct polycondensation of bis(p-phenylthio)dibenzoic acid, 4,4′-{sulphonylbis(p-phenylthio)}dibenzoic acid and 4,4′-{carbonylbis(p-phenylthio)}dibenzoic acid with various aromatic diamines in triphenylphosphite-pyridine systems. The polymers were characterized by inherent viscosity, i.r. spectra, elemental analysis, solubility, differential scanning calorimetry, thermogravimetry and wide angle X-ray diffractometry. © 1993.