화학공학소재연구정보센터
Thermochimica Acta, Vol.471, No.1-2, 20-25, 2008
Excess molar volumes and excess molar enthalpies of binary mixtures for 1,2-dichloropropane+2-alkoxyethanol acetates at 298.15 K
The excess molar volumes V-m(E) and excess molar enthalpies H-m(E) over the whole range of composition have been measured for the binary mixtures formed by 1,2-dichloropropane (1,2-DCP) with three 2-alkoxyethanol acetates at 298.15 K and atmospheric pressure using a digital vibrating-tube densimeter and an isothermal calorimeter with flow-mixing cell, respectively. The 2-alkoxyethanol acetates are ethylene glycol monomethyl ether acetate (EGMEA), ethylene glycol monoethyl ether acetate (EGEEA), and ethylene glycol monobutyl ether acetate (EGBEA). The V-m(E) of the mixture has been shown positive for EGMEA, 'S-shaped' for EGEEA, being negative at low and positive at high mole fraction of 1,2-DCP, and negative for EGBEA. All the H-m(E). values for the above mixtures showed an exothermic effect (negative values) which increase with increase in carbon number of the 2-alkoxyethanol acetates, showing minimum values varying from -374 J mol(-1) (EGMEA) to -428 J mol(-1) (EGBEA) around 0.54-0.56 mol fraction of 1,2-DCP. The experimental results of H-m(E) and V-m(E) were fitted to Redlich-Kister equation to correlate the composition dependence of both excess properties. In this work, the experimental excess enthalpy data have been also correlated using thermodynamic models (Wilson, NRTL, and UNIQUAC) and have been qualitatively discussed. (C) 2008 Elsevier B.V. All rights reserved.