Synthesis and characterization of sulfonylimide based poly(arylene ether sulfone) copolymers for proton-exchange membrane

The sulfonamide based polymers were prepared by condensation polymerization with sulfonylimide monomer, bisphenol A, bis(4-chlorophenyl)sulfone and potassium carbonate. The sulfonylimide monomer was synthesized from bis(4-chlorophenyl)sulfone, furming sulfuric acid, thionyl chloride, and fluorosulfonylamine. The synthesized polymers showed IEC values of 1.02-1.95 mequiv/g for 20-40% ionic groups. The synthesized membranes showed higher proton conductivities in 80% relative humidity at 80 °C than normal poly(ether sulfone) membrane. Moreover, these membranes shows low water uptake and good dimensional stability. The structure of the synthesized monomer and polymers were investigated by
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H NMR spectroscopy. The surface morphologies were also assessed by atomic force microscope (AFM).