Synthesis and Characterization of Sulfonated Poly(diphenyl ether ketone sulfone)s Containing Dibenzoylbenzene Moiety for Proton Exchange Membrane Fuel Cell

Sulfonated poly (diphenyl ether ketone sulfone) s, SPDPEKSs were successfully synthesized for proton exchange membranes (PEMs). Poly (diphenyl ether ketone sulfone) s, PDPEKSs were prepared by the polycondensation of 4,4'-sulfonyldiphenol with 1,2-bis (4-fluorobenzoyl)-3,6-diphenylbenzene (BFBDPB) and 4-fluorophenylsulfone respectively, at 210 °C using anhydrous potassium carbonate as catalyst in sulfolane. PDPEKSs were followed by sulfonation using chlorosulfonic acid and concentrated sulfuric acid at two step reactions. Different contents of sulfonated unit of SPDPEKS (25, 35, 45 mol% of BFBDPB) were studied by FT-IR, 1H NMR spectroscopy, and thermogravimetric analysis (TGA). The ion exchange capacity (IEC), water uptake and proton conductivity of SPDPEKS were evaluated with increase of degree of sulfonation.