Poly(aryl ether sulfide)s have been produced by nucleophilic aromatic substitution with phenoxide nucleophiles bisphenol A and bisphenol AF, and the activated arylfluorides bis(4-fluorophenyl)sulfide and 2,7-difluorothianthrene. The resulting polymers are thermally stable, amorphous materials that have been characterized by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and gel permeation chromatography (GPC). Moderate molecular weights have been achieved, representative of greater than 98% conversion of arylfluorides. The poly(aryl ether thianthrene)s are flame resistant and self extinguish within 0.2 s upon removal from a flame source. TGA of the poly(aryl ether thianthrene)s in an inert atmosphere result in a char yield greater than 50% at 750 degrees C. The flame resistant properties are more effectively modeled by TGA in an inert atmosphere as compared to TGA in an air atmosphere. The poly(aryl ether thianthrene)s are found to have high refractive index values, 1.61-1.70, depending on wavelength and bisphenol composition. (c) 2006 Elsevier Ltd. All rights reserved.