Cross-linked poly (aryl ether ketone) anion exchange membrane with high ion conductivity by two different functional imidazole side chain

Abstract

A series of poly (aryl ether ketone) polymers (PAEKS) and uncross-linked and cross-linked anion exchange membranes (AEMs) with different contents of 1-allyl-3-methylimidazolium chloride and 1-vinylimidazole were prepared. 1HNMR demonstrated the successful preparation of PAEKS. FT-IR provided proof of successfully prepared AEMs. TEM image and SAXS profile showed that these membranes had good microphase separation structure which provides a good channel for ion transport. At 80 °C, the ion conductivity of C-S-Im-PAEKS-3 membrane reached 0.1357 S/cm. Compared with the cross-linked membrane, the uncross-linked membrane showed higher water uptake and swelling ratio. The cross-linked membranes showed vastly improved mechanical properties and alkaline stability, compared to uncross-linked membrane. Tensile strength of C-S-Im-PAEKS-3 membrane reached 31.3 MPa. After soaking the series of membranes in 2 M NaOH solution at 80 °C over 400 h, the ion conductivity of C-S-Im-PAEKS-3 membrane still reached 0.0936 S/cm at 80 °C. In addition, the cross-linked membranes also showed good thermal stability, which promoted the development of anion exchange membrane fuel cells (AEMFCs).