Chloromethylbenzoylation as a simple way to poly(aryl ether)s with side-chain-type benzylic cationic groups for anion-exchange membranes

To circumvent the shortcomings of traditional synthetic routes in the field of anion-exchange membranes (AEMs), a novel approach termed chloromethylbenzoylation has been proposed. Via chloromethylbenzoylation, side-chain-type benzylchloride groups could be directly incorporated into a broad scope of poly(aryl ether) substrates, such as poly(resorcinol ether ketone), poly(naphthalene-2,7-diol ether ketone), poly(resorcinol ether sulfone), and commercial poly(phenylene oxide). As a showcase, chloromethylbenzoylated poly(resorcinol ether ketone) was aminated to obtain side-chain-type AEM, which exhibited higher conductivity, much lower swelling and better alkaline stability when compared with main-chain-type AEMs prepared via traditional chloromethylation of PEEK. This simple and unprecedented approach provides a facile way to high performance AEMs with side-chain-type benzylic cationic groups, without using toxic or costly reagents.