Synthesis, characterization and thermophysical properties of novel 2′, 3′-N-epoxypropyl- N-methyl-2-oxopyrrolidinium acetate ionic liquid and their binary mixtures with water or methanol

Abstract

Novel 2′, 3′-N-epoxypropyl-N-methyl-2-oxopyrrolidinium acetate ([EPMpyr]+[OAC]−) ionic liquid (IL) was successfully synthesized and characterized by FTIR, 1H NMR, 13C NMR and elemental analysis. This ionic liquid was utilized to produce binary mixtures with water or methanol, and their density (ρ), viscosity (η), velocity of sound (u) and refractive index (nD) were measured at varied temperatures from 288.15 to 313.15K, at atmospheric pressure of P=0.1MPa. This investigation resulted in significant thermo-physical data being measured for pure IL, water, methanol and its binary mixtures of water or methanol over the entire range of mole fractions at fixed temperature and atmospheric pressure. Thermodynamic physicochemical properties of excess molar volume (VmE), isentropic compressibility (ks), deviation in isentropic compressibilities (∆ks), and intermolecular free length (Lf), were computed from the resulting experimental data of density and speed of sound. Furthermore, the calculated thermodynamic properties from these experimental data were successfully correlated using the Redlich-Kister equation. The obtained data were analyzed and interesting information about the influence of the functional group interactions and hydrogen bonds between IL and solvents were studied. The correlations and resulting data gave insight about the molecular interactions of binary mixtures as well as possible new applications for pyrrolidonium based ILs.