Highly conductive and stable anion-exchange membranes based on crosslinked poly(arylene ether sulfone)-block-poly(phenylene oxide) Networks

In the field of the developments of next-generation polymer electrolyte membranes, high conductivity is often regarded as the first important performance requirement. There is still a huge challenge to face, which is hard to achieve the balance between high ion conductivity (mainly related to ion-exchange capacity IEC]) and good mechanical-dimensional stability (represented by swelling ratio SR]). Here, a family of crosslinked block polyelectrolytes consisting of hydrophobic rigid poly(arylene ether sulfone) segments to ensure enough dimensional stability and hydrophilic poly(phenylene oxide) segments bearing long-flexible chains with high-density multications to serve as crosslinker and carrier for ion transport are prepared. The polyelectrolyte with an IEC of 3.04 mmol g⁻¹ exhibits a high hydroxide conductivity of 126 mS cm⁻¹ and a low SR of 8.6% at 80 °C. No obvious degradation below 200 °C is observed, and maximum tensile strength reaches 28.4 MPa. As a conclusion, these crosslinked membranes based on well-designed block polyelectrolytes exhibit an excellent combination of high ion conductivity and good mechanical-dimensional stability to meet the performance requirements for the application of anion-exchange membranes. © 2020 Wiley Periodicals, Inc. J. Polym. Sci. 2020 , 58, 391–401