A Polyketone-based Anion Exchange Membrane for Electrochemical Applications: Synthesis and Characterization

An anion exchange membrane (AEM) was made with a modified polyketone (PK). AEMs of polyamines were prepared in a three-step procedure: (I) PK synthesis using ethylene and carbon monoxide, supported by a Pd catalyst, followed by the introduction of 1,2-diaminopropane to yield the polymeric amines; (II) solvent casting of the modified PK with a low degree of amination; (III) iodomethylation to form the AEM (PK-PDAPm(I)), followed by ion exchange with KOH (PK-PDAPm(OH)). The structure of the modified polyketone was characterized using FT-IR, and UV-vis spectroscopy, demonstrating the successful introduction of amine in the PK. The conductivity of the AEM was studied using broadband electric spectroscopy (BES) in the temperature range from -100 to 120 °C: the highest value of 9 × 10-4 S·cm-1 was reached at 120 °C for the ionic conductivity of PK-PDAPm(I), followed by PK-PDAPm(OH) with values of the same order of magnitude (10-4 S·cm-1). Thermogravimetry showed that the material is thermally stable up to 200 °C.