Polymeric ionic liquids based on ether functionalized ammoniums and perfluorinated sulfonimides

A new family of polymeric ionic liquids (PILs) based on alkyl and alkyl ether substituted ammoniums and perfluorinated sulfonimides (i.e., bis(fluorosulfonyl)imide (FSI − ), and bis(trifluoromethanesulfonyl)imide (TFSI − )) have been synthesized by polymerization of the corresponding ionic liquid monomers (ILMs). Their structures and compositions have been characterized by 1 H and 19 F NMR, FTIR and viscosity-average molecular weight ( M v ). The physicochemical properties of both the ILMs and the PILs have been studied in terms of thermal stability, phase transition, and ionic conductivity . All the prepared ILMs and PILs reveal excellent thermal stabilities to greater than 250 °C. The PILs containing alkyl ether side unit show significant decrease in glass transition temperature ( T g ), the values of T g of the alkyl ether based-PILs are all significantly lower by 10–77 °C in magnitude than those of the corresponding alkyl based ones. The ionic conductivity of alkyl ether based-PILs in the best case increases up to 4.0 × 10 −6  S cm −1 at 30 °C, and reaches 7.6 × 10 −5  S cm −1 at 60 °C, and outperform their ammonium counterparts with alkyl side chain that were synthesized as references.