Membranes based on polybenzimidazole and protic ionic liquid: preparation and properties

Proton-conducting membranes based on polybenzimidazole and N-butylimidazolium triflate ionic liquid with different molar ratios of the components were prepared by solution casting. Phase transitions as well as thermal and electrochemical stability of the membranes were studied. The temperature dependences of the membrane conductivity were obtained. All the membranes were thermally stable up to 180 °C. Their conductivities at 145 °C varied from 0.7 to 1.55 mS cm−1 depending on the molar ratio of the components.