Vapour pressures and enthalpies of vaporization of alkylphenols

Abstract The vapour pressures of 2-isopropyl-, 4-isopropyl-, 2-(2-amyl)-, 2- tert -butyl-, and 2,4-di- tert -butylphenol were found. An analysis of literature enthalpies of vaporization and vapour pressures was made. The coefficients of approximate relations of different kinds were found for the description of ( p , T ) of alkylphenols. The possibility of using a four-parameter equation in extrapolating experimental results to lower temperatures was corroborated. The ability of the Pitzer and Lee-Kesler equations, developed for normal liquids (non-polar and non-associating), to predict the vapour pressures and enthalpies of vaporization of alkylphenols in narrow isomeric groups was shown. The type of correlation relation for the prediction of the said properties of various representatives of the alkylphenol series was suggested. The possibility was shown of predicting enthalpies of vaporization of alkylphenols on the basis of valid results for alkylbenzenes. The type of the temperature relation of the constants of the additive scheme for different groups of compounds was established.