REVISION OF INTERACTION PARAMETERS FOR ESTIMATING THE ENTHALPIES OF MIXTURES OF BENZYL ETHANOATE PLUS N-ALKANES OR 1-CHLOROALKANES USING THE UNIFAC MODEL WITH PRESENTATION OF NEW EXPERIMENTAL-DATA

A theoretical and experimental study of the mixing enthalpies at 298.15 K and atmospheric pressure for binary systems composed of benzyl ethanoate and twelve n-alkanes (from C6 to C-17), and benzyl ethanoate and five 1-chloroalkanes (from C4 to C-8) is presented. The results showed that all the systems were endothermal and that the h(E) values increased in a quasi-linear fashion with the number of -CH2- groups in both the n-alkane and the 1-chloroalkane. The data were analyzed using two versions of the UNIFAC group-contribution model, establishing new values for the aromatic/ester and aromatic/chloride interactions. The aromatic groups were represented as ACH and ACCH2, the ester group as CH3COO, and the chloride group as Cl and CCl. Using the new interaction pair values in the calculations produced overall improvements of the order of 50% in the predictions compared with those of the original model. In no case did the error in the h(E) estimates calculated with these new values exceed 6%.