Thermophysical Properties of Glycols and Glymes

Abstract

Experimental data for density, viscosity, refractive index and sound speed of 11 glycols and glymes were measured in the temperature range between (283.15 and 373.15) K and at atmospheric pressure. The compounds evaluated include ethylene glycol (EG), diethylene glycol (DEG), triethylene glycol (TriEG), tetraethylene glycol (TeEG), ethylene glycol ethyl ether (EGEE), diethylene glycol methyl ether (DEGME), diethylene glycol dimethyl ether (DEGDME), diethylene glycol ethyl ether (DEGEE), diethylene glycol diethyl ether (DEGDEE), triethylene glycol dimethyl ether (TriEGDME), and tetraethylene glycol dimethyl ether (TeEGDME). Additionally, derivative properties, such isobaric thermal expansion coefficient and isentropic compressibilities were also estimated and discussed. The compounds evaluated were selected to evaluate the impact of molecular structure changes on their thermophysical properties. Effects like the increase in the number of ethoxy groups, shown to lead to an increase of the density, molar volume, viscosity, and refractive index, or the loss of the hydroxyl groups through the substitution of the hydroxyl groups hydrogen by a methyl or ethyl group, shown to lead to a significant decrease on the density, viscosity, and sound speed, are evaluated and discussed.