Synthesis and thermal characterization of new ammonium–imidazolium dual dicyanamide-based ionic liquids

Novel dual dicyanamide-based ionic liquids consisting of coupled ammonium–imidazolium cationic structures were synthesized and their thermal properties were studied. The molecular structures of these compounds were identified by NMR , FT-IR and CHN analysis . Viscosity measurements showed that the new ionic liquid with vinylimidazolium group has lower viscosity than the ionic liquid with methylimidazolium group. However, the densities of the new synthesized compounds are almost same. Thermal behaviors and heat capacities of these ionic liquids were also investigated by thermogravimetry (TGA) and differential scanning calorimetry (DSC). The results suggest that the new ionic liquids have thermal stabilities up to 200 °C, as well as reasonable heat capacities in the range 25 to 100 °C.