A novel crosslinking organic–inorganic hybrid proton exchange membrane based on sulfonated poly(arylene ether sulfone) with 4-amino-phenyl pendant group for fuel cell application

A series of novel organic–inorganic hybrid proton exchange membranes were prepared from sulfonated poly(arylene ether sulfone) (Am-SPAES) with 4-amino-phenyl pendant group, (3-isocyanatopropyl)triethoxysilane (ICPTES) and tetraethoxysilane (TEOS) using a sol–gel method. The reactive ICPTES was used to react with the amino pendant groups of Am-SPAES to form covalent bonds between Am-SPAES and SiO2, which could effectively improve the compatibility between the polymer matrix and the inorganic SiO2 phase. The obtained hybrid membranes exhibited excellent thermal and oxidative stability. The mechanical properties of the membranes were enhanced and the swelling ratio of the membranes was reduced by introducing the cross-linking network structure. Especially, these hybrid membranes possessed higher water uptake and proton conductivities compared to the pristine Am-SPAES membrane when the SiO2 content was 3 and 6 wt%, whereas the same properties of the obtained hybrid membranes decreased when the SiO2 content was 10 wt%. All of the membranes showed much lower methanol permeability than Nafion 117 did. In addition, the dispersion of the inorganic particles (SiO2) in the Am-SPAES matrix could be improved by the strong covalent interactions between Am-SPAES and SiO2.

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► Novel Am-SPAES with 4-amino-phenyl pendant group was prepared.
► The membranes combined organic–inorganic hybrids with covalent cross-linking.
► Membranes exhibited high conductivity, excellent thermal and oxidative stability.