Preparation and characterization of side-chain poly(aryl ether ketone) anion exchange membranes by superacid-catalyzed reaction

The poly(aryl ether ketone) with spatial cardo structure is prepared from 4,4?-bis(phenoxy)benzophenone and 1(4-bromobutyl)indoline-2,3-dione through a facile polyhydroxyalkylation reaction catalyzed by superacid. The number average molecular weight of the resultant polymer is achieved as high as 105.6 kg mmol-1. Three anion exchange membranes were prepared by reacting the polymer with trimethylamine, N-methyl-piperidine, and N, N,N',N',N'-pentaethylguanidine, respectively. Among the prepared membranes, N-methyl-piperidine based anion exchange membrane exhibited the highest OH- conductivity of 99.8 mS cm(-1) at corresponding IEC of 1.54 meq g(-1). In addition, the prepared membranes also exhibit excellent mechanical properties, in which the tensile strength and elongation at break can reach up to 50 MPa and 35%, respectively. Moreover, the anion exchange membranes exhibited good alkaline stability. When they were treated with 1 M KOH at 60 degrees C for 600 h, their conductivity decreased by less than 5%.

Automated summary

In this study, poly(aryl ether ketone) with spatial cardo structure was prepared via a facile polyhydroxyalkylation reaction catalyzed by superacid, leading to the synthesis of three different anion exchange membranes. Among them, the N-methyl-piperidine based anion exchange membrane exhibited the highest OH- conductivity. The membranes also demonstrated excellent mechanical properties and good alkaline stability, with conductivities decreasing by less than 5% after treatment with 1 M KOH at 60 degrees C for 600 hours.