Excess molar volumes and excess molar enthalpies of the binary mixtures of 1,2-dichloropropane with di- and triethylene glycol mono-alkyl ethers at T=298.15K

• Published in: Fluid phase equilibria 2009-11, Vol.285 (1-2), p.30-35
• Main Authors: Sen, D, Kim, M G
• Format: Article
• Language: English
• Subjects: Binary mixtures; Density; Ethers; Glycols; Heat flux; Mathematical analysis; Mathematical models; Triethylene glycol
• ISSN: 0378-3812
• DOI: 10.1016/j.fluid.2009.06.018

The excess molar volumes V sub(m) super(E) and excess molar enthalpies H sub(m) super(E) at T=298.15K and atmospheric pressure for the binary systems of 1,2-dichloropropane (1,2-DCP) with di- and triethylene glycol mono-alkyl ethers have been determined by measuring density and heat flux, respectively. The density has been measured by using a digital vibrating-tube densimeter, whereas heat flux measurements have been carried out by using an isothermal calorimeter with a flow-mixing cell. The diethylene glycol mono-alkyl ethers are 2-(2-alkoxyethoxy)ethanols: diethylene glycol mono-propyl ether (DEGMPE), diethylene glycol mono-butyl ether (DEGMBE), and the triethylene glycol mono-alkyl ethers are 2-(2-(2-alkoxyethoxy)ethoxy)ethanols: triethylene glycol mono-methyl ether (TEGMME), triethylene glycol mono-ethyl ether (TEGMEE), and triethylene glycol mono-butyl ether(TEGMBE). It was found that both V sub(m) super(E) and H sub(m) super(E) values of the binary mixtures are negative over the whole composition range except for the mixture with very high mole fraction of 1,2-DCP(x sub(1)) in both DEGMPE and DEGMBE. In the case of 2-(2-(2-alkoxyethoxy)ethoxy)ethanols, the negative values of V sub(m) super(E) and H sub(m) super(E) continue to increase with an increase of the alkyl chain length of these alkoxyethanols. The minimum values of V sub(m) super(E) shift from -0.1939cm super(3)mol super(-) super(1) for the mixture with DEGMPE to -0.40cm super(3)mol super(-) super(1) for the mixture with TEGMBE at x sub(1)=0.40-0.50. Also, the minimum negative values of H sub(m) super(E) have been shown ranging from -472.9Jmol super(-) super(1) (DEGMBE) to -800.5Jmol super(-) super(1) (TEGMBE) at x sub(1)=0.40-0.50. The experimental results of both H sub(m) super(E) and V sub(m) super(E) were fitted to the Redlich-Kister equation. The experimental H sub(m) super(E) data were also fitted to three local-composition models (Wilson, NRTL, and UNIQUAC). It was found that among these three models, the NRTL equation provides the most appropriate correlating result.