Aromatic polyethers, polysulfones, and polyketones as laminating resins. III

Abstract 4,4′‐Diphenoxydiphenylsulfone was polymerized with isophthaloyl chloride and terephthaloyl chloride in Friedel‐Crafts polymerizations. These polymers had 5‐cyanoisophthaloyl units in the backbone obtained either by using 1,3‐bis(p‐phenoxybenzoyl)‐5‐cyanobenzene or 5‐cyanoisophthaloyl chloride as part of the acid chloride monomer. A terpolymer having 22 wt‐% 5‐cyanoisophthaloyl unit was also prepared from the Friedel‐Crafts polymerization of 1,3‐bis(p‐phenoxybenzenesulfonyl)benzene and 5‐cyanoisophthaloyl chloride. These terpolymers were crosslinked through heating to give insoluble products which proved to be thermally less stable than the uncrosslinked polymers.