Physicochemical Characterization of New Sulfate Ionic Liquids

In this work, the ionic liquids 1-ethyl-1-methylpyrrolidinium ethylsulfate [EMpyr][ESO(4)], 1-n-butyl-1-ethylpyrrolidinium ethylsulfate [BEpyr][ESO(4)], 1-n-butyl-1-methylpyrrolidium methylsulfate [BMpyr][MSO(4)], and triethylmethylammonium methylsulfate [E(3)MN][MSO(4)] were synthesized, and their experimental densities, speeds of sound, dynamic viscosities, and refractive indices were studied as a function of temperature at atmospheric pressure. Thermal expansion coefficient, molar volume, and molar refraction of these ionic liquids were calculated from the experimental density and refractive index values. A thermal analysis for pyrrolidinium and ammonium-based ionic liquids at temperatures between T = (253.15 and 363.15) K is presented.