Résumé
Fuel cells are one of the most attractive approaches to energy conversion, due to their high flexibility and their easy handling. An introduction first summarizes the overall situation of perfluorosulfonic acid membranes, as well as their prospects in fuel cell systems and cost analysis. Then, after a section dedicated to their challenges, this chapter focuses on fluorinated materials for quasianhydrous PEMFC. Hence, a new family of proton conducting fluorocopolymers grafted by azole side functions, such as (benz)imidazole and 1H-1,2,4-triazole, was synthesized through grafting various (benz)imidazole and 1H-1,2,4-triazole derivatives onto poly(iodoethyl vinyl ether–alt–chlorotrifluoroethylene) copolymers. These fluorofunctional copolymers were characterized by spectroscopy, thermal analyses, and were involved in the elaboration of blend membranes with sulfonated PEEK (sPEEK). Physico-chemical, thermal, and electrochemical properties of the three series of resulting membranes were studied to insure the influence of the nature of the azole group onto the membrane thermal properties, microstructure, water uptake, and proton conductivities. Membranes based on a fluorinated copolymer containing triazole displayed significantly higher proton conductivities (up to 7 mS.cm−1 at 140 °C and low relative humidity (< 25 %)). A further study on novel blend membranes from such a system above containing carbonate side-groups and crosslinked by telechelic diamines displayed lower swelling rates and better potential mechanical properties than the uncrosslinked ones.