Method for preparing polyether copolymers with polycarbonates and polyarylates

Copolymers of polycarbonates or polyarylates with polyether polymers such as polyethersulfones, polyetherketones, and polyetherimides are prepared by reaction of the polyether polymer-forming reagents, e.g., bisphenol A disodium salt and bis(4-chlorophenyl) sulfone, in the presence of the polycarbonate or polyarylate. The reaction may take place in a dipolar aprotic solvent, or in a water-immiscible aromatic solvent in the presence of a phase transfer catalyst, preferably a hexaalkylguanidinium halide. Hydroxy-terminated polyether oligomers may be produced from the copolymers by saponification of carbonate or ester groups.