Synthesis and Characterization of Multiblock Sulfonated Poly(arylenethioethersulfone) Copolymers for Proton Exchange Membranes

Synthesis and characterization of multiblock sulfonated poly(arylenethioethersulfone) copolymers for proton exchange membranes (PEMs) were reported. Multiblock SPTES-50 copolymer was prepared during the study to balance the distribution of hydrophobicity and hydrophilicity along the polymer backbone. The study used 4-fluorophenylsulfone, potassium carbonate, tetramethylene sulfone, and N,N-dimethylacetamide as received, while 4,4-thiobisbenzethiol was recrystallized from toluene and dried in vacuum before using. It was observed that membranes of multiblock SPTES-50 copolymers cast from a DMAc solution indicated a higher water uptake and higher proton conductivity. AFM and TEM studies indicated that multiblock SPTES-50 copolymers formed a different morphological structure with high proton conductivity compared to random SPTES-50 copolymers.