The effect of ionic bond on anion exchange membrane: Enhanced hydrophilicity and structural rearrangement of blending membrane

• The incorporation of PVA influences the characteristics of the QPPOx-PVAy blended AEMs. • The blend AEMs showed improved alkaline stability in 2 M NaOH at 60°C. • The blend AEMs displayed enhanced ion conductivity and power density than QPPO . For the commercialization of anion exchange membrane fuel cells (AEMFCs), the anion exchange membrane (AEM), which is a key component of AEMFCs, requires not only excellent ion conductivity but also high alkaline stability. Therefore, in this study, a hybrid membrane composed of quaternized poly(phenylene oxide) (QPPO) with a dense ion sites and polyvinyl alcohol (PVA), known for its superior chemical and mechanical properties, is prepared. The QPPO x -PVA y AEMs (where x and y represent the weight ratio of QPPO and PVA) forms hydrogen bonds or electrostatic interactions through a dehydration reaction between the quaternary ammonium group of QPPO and the hydroxyl group of PVA. This network bonding, resulting in enhanced hydrophilicity and structural rearrangement, improves the dimensional and chemical stability of the membrane. Among the prepared AEMs, QPPO 85 -PVA 15 AEM exhibits high ionic conductivity of 79.8 mS cm −1 at 80 °C under 100 % RH, a low dimensional change, and appropriate mechanical strength. In addition, ion conductivity of QPPO 85 -PVA 15 AEM retains 86.3 % of its initial ion conductivity after 1000 h in 2 M NaOH conditions. Thus, overall results demonstrate that the appropriate incorporation of PVA is effective in producing AEMs with excellent dimensional stability and high performance.