New Polyethylene Based Anion Exchange Membranes (PE–AEMs) with High Ionic Conductivity

This paper discusses a new class of high performance polyethylene-based anion exchange membranes (PE–AEMs) that contain a wide concentration range of pendant (flexible) ammonium chloride (NR3+Cl–) groups and with or without a cross-linked PE matrix structure. The chemistry involves a metallocene-mediated polymerization of ethylene, silane-protected α,ω-amino-olefin [CxN(SiMe3)2], with or without styrenic diene (cross-linker), to form ethylene/CxN(SiMe3)2 copolymers and ethylene/CxN(SiMe3)2/diene terpolymers, respectively. The resulting co- and ter-polymers were completely soluble in common organic solvents and were solution-casted into uniform films (thickness, 50–70 μm; without backing material) and then thermal cross-linked in ethylene/CxN(SiMe3)2/diene case, further interconverting the silane-protected amino groups into the desired −NR3+Cl– groups (R: H, CH3, and C3H7) under solid state conditions. The resulting PE–NR3+Cl– and cross-linked x-PE–N(CH3)3+Cl– membranes were systematically studied to under...