September 30, 2016 - 3:15pm - 4:00pm
Fuel cell (FC) is an energy converter (exchanger) that converts, in an electrochemical process, the energy of an oxidation reduction to electrical energy, heat, and water as the only waste product. Most know protonic membranes for FCs are perfluorosulfonic acid membranes (PFSAs)1. This presentation will first recall these PFSAs and then will develop recent studies regarding protonic as well as alkaline, and quasi-anhydrous FCs (Scheme 1)2. In this context, original proton conducting fluorocopolymers grafted by azole functions (imidazole, benzimidazole, 1H-1,2,4-triazole) were synthesized through grafting poly(iodoethyl vinyl ether alt chlorotrifluoroethylene) copolymers by azole derivatives. Imidazole, benzimidazole and 1,2,4-triazole functionalized copolymers were used in blend membranes with sulfonated PEEK (sPEEK).3 Properties of the three series of membranes were comprehensively studied to evidence the influence of the nature of the azole group on membrane microstructure. Proton conductivities of blend membranes comprising a fluorinated polymer component functionalized with triazole was significantly higher than those with imidazole or benzimidazole moieties, and detailed characterizations have identified an optimal composition in terms of the basic (-NH):acidic (- SO3H) groups ratio of 1.7 in this system, where the proton conductivity at 140 °C and at low relative humidity (< 25 %) reached 7 mS.cm-1 for a blend membrane containing 60 wt% of sPEEK and 40 wt% of poly(IEVE-alt-CTFE)-g-1H-1,2,4-triazole-3-thiol95% copolymer.