In the pursuit of better functioning anion exchange membranes, pendent hexyl side chains were introduced onto terpolymers composed of perfluorohexylene (PHB), hexafluoroisopylidene (BAF), and quaternized fluorene groups. The resulting QBPHBA membranes exhibited similar water absorbability and gas (hydrogen and oxygen) permeability to those of the previous terpolymer-based AEMs without aliphatic side chains. In contrast, hexyl groups contributed to improving the OH- conductivity. The highest OH- conductivity (163mScm(-1) at 80 degrees C) was achieved with the QBPHBA membrane with 2.49 meq. g(-1) of ion exchange capacity (IEC). Furthermore, mechanical properties were also improved; the strain at break increased from 12% (BAF-containing copolymer membrane) to 284%. The terpolymer composition for the best-balanced properties turned out to be 17mol% of the side-chain substituted PHB groups, in particular, with high IEC (2.49 meq. g(-1)).
展开▼
