Polymer Electrolyte Membrane Based on Sulfonated Poly(Ether Ketone Ether Sulfone) (S-PEKES) with Low Methanol Permeability for Direct Methanol Fuel Cell Application

摘要

Poly(ether ketone ether sulfone), (PEKES), was synthesized by the nucleophilic aromatic substitution polycondensation between bisphenol S and 4,4'-difluorobenzophenone (system A), and between bisphenol S and 4,4'-dichlorobenzophenone (system B). The oxidative stability was characterized by using a Fenton's reagent. S-PEKES membranes show a higher thermal stability than that of Nation 117 and comparable to that of S-PEEK 150XF. The proton conductivity values of S-PEKES of the highest DS are comparable to those of Nation 117 and S-PEEK. The methanol permeability of the synthesized and fabricated S-PEKES membrane is lower than that of Nation 117 by at least an order of magnitude.