Thermophysical properties of 1,2,4-trimethylbenzene in admixtures with 1-butanol or 2-butanol at high pressures

The systems of 1-butanol or 2-butanol + 1,2,4-trimethylbenzene were characterized measuring densities and isobaric heat capacities at high pressures. Densities of 2-butanol and 1,2,4-trimethylbenzene and the binary systems 1-butanol or 2-butanol + 1,2,4-trimethylbenzene were measured at the ranges p = (0.1-140) MPa and T = (273.15-333.15) K. For these measurements, a high-pressure vibrating tube densimeter was used and data were successfully correlated with the empirical Tammann-Tait equation. In order to complete the characterization, isobaric heat capacities were measured over the range of (0.1-25) MPa at two different temperatures (293.15 and 313.15) K for the same pure compounds and binary mixtures. These measurements were performed in a high-pressure automated flow calorimeter. Excess molar heat capacities were evaluated for the mixtures and a positive deviation from the ideality was obtained for both systems.