Preparation and Characterizations of Cross-linked Sulfonated Poly(ether ether ketone)/Partially Fluorinated Sulfonated Poly(aryl ether sulfone)Blend Membranes

A type of blend and cross-linked proton exchange membrane (CMB) based on sulfonated poly (ether ether ketone) (SPEEK)/partially fluorinated sulfonated poly (aryl ether sulfone) (SPFAES) were prepared, and the properties including water uptake, swelling ratio, mechanical properties, thermal properties, proton conductivity, chemical stability and fuel cell performances of the CMBs were evaluated. The cross-linking structure was constructed in the blend system by adding dehydrating agent during solution casting. The results indicate that the CMB membranes all exhibit excellent mechanical strength in dry state and greatly improved physicochemcial stability due to the good compatibility and dispersion between SPEEK and SPFAES, and the rearrangement and cross-linking of polymer chains. With low ion exchange capacity (1.21-1.51 mmol/g), the proton conductivities of CMB membranes reach 122-219 mS/cm (80 degrees C), and the maximum power density of the CMB4 membrane achieves 530.5 mW/cm(2) (80 degrees C) in a single hydrogen-oxygen fuel cell.