Vapor pressures, enthalpies of vaporization, and critical parameters of a series of linear aliphatic dimethyl esters of dicarboxylic acids

Abstract

Vapor pressures and the molar enthalpies of vaporization of the linear aliphatic dimethyl esters of dicarboxylic acids CH3-CO 2-(CH2)n-CO2-CH3 with n = (0 to 8) have been determined by the transpiration method. A linear correlation of enthalpies of vaporization (at T = 298.15 K) of the esters studied with the number n and with the Kovat's indices and has been found. The critical temperatures and pressures of the esters with n = (0 to 6) and n = 8 have been measured by the pulse-heating method with the residence times ranging from (0.03 to 1) ms. Experimental data on the critical properties are compared with the estimations by group contribution methods by Constantinou and Gani and by Marrero and Gani. Both methods considerably underestimate the critical temperatures of the esters studied; however, the method by Marrero and Gani provides the prediction of the critical pressures of the esters with an average absolute error approximately equal to the uncertainty of the measurements. © 2006 American Chemical Society.