Determination of Vaporization Enthalpies of the Branched Esters from Correlation Gas Chromatography and Transpiration Methods

Abstract

The temperature dependencies of retention indices of a set of 80 esters with branched molecular structures were measured on a nonpolar gas chromatographic column. The correlation gas chromatography method and reliable data set of 16 esters selected from the literature were used to derive a correlation for the prediction of the standard molar enthalpies of vaporization at the temperature T = 298.15 K. Experimental values of for 64 branched esters were obtained with the help of this correlation. The vaporization enthalpies of isopentyl acetate, ethyl hexanoate, and neopentyl pivalate were additionally obtained by the transiration method from the temperature dependence of the vapor pressure measured in a flow system and used for checking the validity of the correlation gas chromatography method.