Sulfonated poly(aryl sulfide sulfone)s containing trisulfonated triphenylphosphine oxide moieties for proton exchange membrane

Abstract A series of sulfonated poly(aryl sulfide sulfone)s containing trisulfonated triphenylphosphine oxide moieties (TS-PASS-xx) were prepared by the nucleophilic aromatic substitution reaction using bis(4-fluoro-3-sulfonatedphenyl)-(3-sulfonated phenyl) phosphine oxide trisodium salt, bis(4-fluorophenyl) sulfone and 4,4'-thiobis(benzenethiol) as starting materials. The intrinsic viscosities of these polymers were between 0.59 to 0.85 dL/g. All the sulfonated polymers had good solubility and film formation ability in some solvents. They could afford flexible proton exchange membranes by solution-casting. Their chemical structures and some properties, including water uptake, swelling ratio, proton conductivity, and thermal and chemical oxidation stabilities, were investigated. The representative sulfonated poly(aryl sulfide sulfone) with 30% degree of sulfonation (TS-PASS-30) showed good combination properties: the water uptacke was 49.1%, the swelling ratio was 15.8% and the proton conductivity was 178 mS/cm. Moreover, TS-PASS-30 also has excellent thermal and chemical oxidative stabilities.