Direct polymerization of novel functional sulfonated poly(arylene ether ketone sulfone)/sulfonated poly(vinyl alcohol) with high selectivity for fuel cells

Abstract

Novel cross-linked membranes based on sulfonated poly(arylene ether ketone sulfone) containing pendant amino groups (Am-SPAEKS) and sulfonated poly(vinyl alcohol) (SPVA) as macromolecular cross-linkers were fabricated for potential application value in fuel cells. Water uptake, dimensional stability, thermal stability, gel fraction, methanol permeability and proton conductivity were thoroughly studied. Both atomic force microscopy (AFM) phase images and transmission electron microscopy (TEM) were used to evaluate the morphology of the membranes. The methanol permeability coefficients of the Cr-Am/S-80 membrane, Am-SPAEKS membrane cross-linked with 80 wt% SPVA, are only 0.32 × 10⁻⁷ cm² s⁻¹ at 20 °C and 0.96 × 10⁻⁷ cm² s⁻¹ at 60 °C, respectively. These values are much lower than that of the Am-SPAEKS membrane (9.86 × 10⁻⁷ cm² s⁻¹ at 20 °C and 19.91 × 10⁻⁷ cm² s⁻¹ at 60 °C). The proton conductivities of the cross-linked membranes were above 10⁻² S cm⁻¹ at 80 °C. In addition, the cross-linked membrane exhibited high selectivity, further proving its potential application value in proton exchange membrane fuel cells.