Synthesis, Characterization and Thermophysical Properties of 1-Butylpyridinium Room Temperature Ionic Liquids

Room temperature ionic liquids (RTILs) that comprise entirely of ions are under intense investigations owing to their special properties such as high thermal stability, non-flammable and non-detectable vapor pressure under normal conditions. Several potential areas of RTILs’ application include gas and liquid separations, catalytic reactions, electrolyte/fuel cell and many others. However, in order to utilize ionic liquids for commercial applications, their accurate and reliable basic thermophysical properties are essential for the design and scale up of process equipments. In this paper, the synthesis and characterization of RTILs based on 1-butylpyridinium [C4py] with trifluoroacetate [TfAc], dicyanamide [Dca] and acetate [Ac] are presented. The density, dynamic viscosity, refractive index and decomposition temperatures are also reported. The density,  and dynamic viscosity,  were measured at T = (293.15 to 353.15) K and refractive index nD, was measured at T = (293.15 to 333.15) K at atmospheric pressure. Empirical correlations are used to represent the experimental results. The values of thermal expansion coefficients were calculated from the experimental density values. The experimental values of density and refractive index were found to decrease linearly with increasing temperature. The thermal decomposition temperatures were determined using thermogravimetric analyzer (TGA) at a heating rate of (10 and 20) K.min-1. The results were compared with other 1-butylpyridinium ionic liquid with different anion.