Thermodynamic Properties of <i>N</i>-Alkoxyethanols + Organic Solvent Mixtures. X. Liquid−Liquid Equilibria of Systems Containing 2-Methoxyethanol, 2-(2-Methoxyethoxy)ethanol or 2-(2-Ethoxyethoxy)ethanol, and Selected Alkanes

Abstract

Liquid−liquid equilibria (LLE) data are reported for 2-methoxyethanol + heptane, + methylcyclohexane, or + 2,2,4-trimethylpentane and for 2-(2-methoxyethoxy)ethanol + 2,2,4-trimethylpentane and 2-(2-ethoxyethoxy)ethanol + methylcyclohexane mixtures between 281.8 K and the upper critical solution temperatures (UCSTs). The coexistence curves were determined visually. They have a rather horizontal top and are skewed to the region of higher mole fractions of the alkoxyethanol, x1, for systems with 2-methoxyethanol, and to the region of lower x1 values for the mixtures including the other two hydroxyethers. The (x1, T) data were fitted to the equation T = Tc + k|y − yc|m, where y = αx1/{1 + x1(α − 1)} and yc = αx1c/{1 + x1c(α − 1)}. Tc and x1c are the coordinates of the critical points fitted together with k, m, and α. Results are briefly discussed on the basis of the existence of inter- and intramolecular H-bonds as well as of dipole interactions, which occur in solutions containing hydroxyethers.