Vapor pressures and thermophysical properties of selected monoterpenoids

A thermodynamic study of selected monoterpenoids, geraniol, β-citronellol, and borneol, is presented in this work. The vapor pressure measurements were performed using two static apparatus over a wide temperature range from 273 to 363 K. Liquid heat capacities were measured by Tian-Calvet calorimetry in the temperature interval from 258 to 355 K. The phase behavior was investigated by DSC from 183 K. The thermodynamic properties in the ideal-gas state were calculated by combining statistical thermodynamics and density functional theory (DFT) calculations. Calculated ideal-gas heat capacities and experimental data on vapor pressure and condensed phase heat capacity were treated simultaneously to obtain a consistent thermodynamic description.