Isobaric vapor-liquid equilibrium and isothermal surface tensions of 2,2 '-oxybis[propane]+2,5-Dimethylfuran

Abstract

Isobaric vapor-liquid equilibrium (VLE) data have been measured for the binary system 2,2'-oxybis[propane] + 2,5-Dimethylfuran at 50, 75, and 94 kPa and over the temperature range 321-364 K using a vapor-liquid equilibrium still with circulation of both phases. Atmospheric surface tension (ST) data have been also determined at 283.15 and 330.15 K using a maximum bubble pressure tensiometer. Experimental results show that the mixture is zeotropic and exhibits slight positive deviation from ideal behavior over the experimental range. Surface tensions, in turn, exhibit negative deviation from the linear behavior. For each isothermal condition, it is observed that the surface tension decreases as the mole fraction of 2,2'-oxybis[propane] increases, whereas at a fixed mole fraction, the surface tension decreases as the temperature increases. The VLE data of the binary mixture satisfy the Fredenlund's consistency test, and the dependence of ST on mole fraction was satisfactorily smoothed using the Redlich-Kister equation. The experimental VLE and ST data were accurately described by applying the square gradient theory to the Cubic-Plus-Association equation of state. This theoretical model was also applied to describe the surface activity of species along the interfacial region, from which it is possible to conclude that only the 2,2'-oxybis[propane] presents an interfacial accumulation which decreases as the concentration of DIPE or temperature increases. (C) 2013 Elsevier B.V. All rights reserved.