Synthetic route to soluble sulfonated poly(arylene sulfone imide)

A synthetic route to high-molecular-weight sulfonated poly(arylene sulfone imide), which cannot be prepared via the direct synthesis of a polyimide moiety due to the presence of electron-deficient groups in the monomers, has been developed. A target polymer was synthesized by the oxidation of a poly(arylene sulfide imide), which was readily synthesized by the conventional synthetic route for polyimides. Notably, because of good solubility of the sulfonyl moieties, the obtained polymer was also highly soluble, and thus it was possible to fabricate a solution-cast polymer film. Therefore, sulfonated poly(arylene sulfone imide)s are potentially soluble sulfonated poly(arylene imide) s for applications where solvent solubility is an issue.