Vapor pressure and thermophysical properties of eugenol and (+)-carvone

In this work, vapor pressures, liquid-phase heat capacities, and phase behavior of two monoterpenoids, (þ)-carvone and eugenol were studied. The vapor pressure experiments were performed using a static method over an environmentally relevant range of temperatures, from 258 K to 308 K. Liquid-phase heat capacities were measured by Tian-Calvet calorimetry between 265 K and 355 K. The phase behavior was investigated by heat-flux differential scanning calorimetry from 183 K. Experimental data were supplemented by ideal-gas thermodynamic properties obtained by combining quantum chemical and statistical thermodynamic calculations. Vapor pressures and heat capacities obtained in this work along with selected literature values were treated simultaneously by multi-property correlation in order to obtain a consistent description of thermodynamically linked properties. To our knowledge, liquid-phase heat capacities and phase behavior of eugenol are reported for the first time in this work.The authors M.F., K.R., V. S., and V.P. acknowledge financial support from the Czech Science Foundation (GACR no. 17-03875S) and specific university research (MSMT No. 20-SVV/2018). The authors S.M.V., O.F., and S.P.P. acknowledge financial support from the project POCI-01-0145-FEDER-006984 e Associate Laboratory LSRE-LCM (UID/EQU/50020/2019) funded by national funds through FCT/MCTES (PIDDAC). S.M.V. also acknowledges FCT for his PhD grant (SFRH/BD/138149/2018).info:eu-repo/semantics/publishedVersio

Thermodynamic Properties of Three Pyridine Carboxylic Acid Methyl Ester Isomers

This article discusses the thermodynamic properties of three pyridine carboxylic acid methyl ester isomers

Reassembling and testing of a high-precision heat capacity drop calorimeter. Heat capacity of some polyphenyls at T = 298.15 K

The description of the reassembling and testing of a twin heat conduction, high-precision, drop microcalorimeter for the measurement of heat capacities of small samples are presented. The apparatus, originally developed and used at the Thermochemistry Laboratory, Lund, Sweden, has now been reassembled and modernized, with changes being made as regarding temperature sensors, electronics and data acquisition system. The apparatus was thereafter thoroughly tested, using benzoic acid and hexafluorobenzene as test substances. The accuracy of the View the MathML sourceCp,m° (298.15 K) data obtained with this apparatus is comparable to that achieved by high-precision adiabatic calorimetry. Here we also present the results of heat capacity measurements on of some polyphenyls (1,2,3-triphenylbenzene, 1,3,5-triphenylbenzene, p-terphenyl, m-terphenyl, o-terphenyl, p-quaterphenyl) at T = 298.15 K, measured with the renewed high precision heat capacity drop calorimeter system. The high resolution and accuracy of the obtained heat capacity data enabled differentiation among the ortho-, meta-, and para-phenyl isomers

Thermodynamic study of selected monoterpenes

A thermodynamic study of important biogenic compounds, (-)-alpha-pinene, (-)-beta-pinene, (-)-cis-verbenol, and (-)-verbenone, is presented in this work. The vapor pressure measurements were performed using the static method over the environmentally important temperature range from 238 to 313 K. The sublimation and vaporization enthalpies were derived from these measurements as well as directly determined by a Calvet high temperature microcalorimeter. Heat capacities of condensed phases were measured by Calvet and drop calorimetry in the temperature interval from 273 to 355 K. The thermodynamic properties of the ideal-gas state were calculated by combining statistical thermodynamics and density functional theory (DFT) calculations. The trends in thermodynamic properties within the group of compounds possessing similar molecular structures are discussed. (C) 2013 Elsevier Ltd. All rights reserved