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

• Published in: Journal of molecular liquids 2015-11, Vol.211, p.831-838
• Main Authors: Fareghi-Alamdari, Reza, Zamani, Faezeh Ghorbani, Shekarriz, Marzieh
• Format: Article
• Language: English
• Subjects: Dicyanamide anion; Heat capacity; Ionic liquids; Thermal gravimetric analyses; Thermal properties
• ISSN: 0167-7322; 1873-3166
• DOI: 10.1016/j.molliq.2015.08.012

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. •We coupled imidazole and ammonium cations to the synthesis of new ionic liquids.•Synthesized ILs have properties of both cations.•Cationic asymmetric structure led to a decrease in the melting temperature.•The dual dicyanamide anion and dicationic structures improve the properties like thermal stability.•Both synthesized ILs have reasonable thermal stability and heat capacity.