Anion conductive aromatic ionomers containing fluorenyl groups

A study was conducted to demonstrate the synthesis of poly(arylene ether sulfone ketone)s containing quaternized ammonio-substituted fluorenyl groups as novel anion exchange membranes (AEM). Chloromethyl groups were successfully introduced at the specific positions of the fluorenyl groups of polyethers through Friedel-Crafts reaction and were converted to quaternized ammonio groups. Ionic conductivity of the polymer membranes bearing various ion exchange capacities (IECs) were also evaluated in water at various temperatures. Precursor poly(arylene ether sulfone ketone) bearing fluorenyl groups (PE) was synthesized by a nucleophilic substitution polymerization 4-fluorophenyl sulfone, 4,4'-difluoro-phenylbenzophenone, and 9,90-bis(4-hydroxyphenyl)-fluorene in the presence of potassium carbonate in dry N,N'-dimethylacetamide (DMAc). The Friedel-Crafts chloromethylation reaction of the pristine polymers was also examined from various angles of the reaction factors.