Preparation and characterization of fluorinated poly(aryl ether oxadiazole)s anion exchange membranes based on imidazolium salts

A series of fluorinated poly(aryl ether oxadiazole)s ionomers based on imidazolium salts (FPAEO-xMIM) were synthesized by quaternization of bromomethylated poly(aryl ether oxadiazole)s (FPAEO-xBrTM) with 1-methyl imidazole as aminating reagent. The anion exchange membranes (AEMs) were prepared by casting method and then immerged in aqueous sodium hydroxide for hydroxide ion exchanging. The structure of the obtained ionomers was characterized by 1H-NMR and FT-IR measurements. The physical and electrochemical properties of the membranes were also investigated. The hydroxide conductivity of FPAEO-xMIM membranes was higher than 10−2 S cm−1 at room temperature, while the water uptake and swelling ratio was moderate even at elevated temperature. TGA analysis revealed that the membranes based on imidazolium salts had good thermal stability.