Alkaline stability of ether bond free fluorene-based anion exchange polymer containing cycloaliphatic quaternary ammonium groups

Quaternary piperidinium cation was incorporated into aryl-ether-bond-free fluorene-based polymer by flexible alkyl side chains to synthesize a highly conductive and chemically stable anion exchange membrane (AEM). The membrane of the OH- form shows good solubility in dimethyl sulfoxide and methanol but not soluble in water. In a fully hydrated state, the OH- conductivity reached 58 mS cm(-1) at 80 degrees C. The results of H-1 NMR spectra revealed that the alkyl-substituted N-methylpiperidinium cationic group was excellent alkaline stable as only 13% cationic group was degraded after 168 h storage in 1 M NaOH solution at 80 degrees C. (c) 2020 Elsevier Ltd. All rights reserved.