Liquid-liquid equilibria for the systems 2-ethoxy-benzenamine + CH3 (CH2)nCH3 (n=6,8,10,12) and 4-ethoxy-benzenamine + CH3(CH2)nCH3 (n=5,6)

Liquid-liquid equilibria (LLE) phase diagrams have been determined for the systems: 2-ethoxy-benzenamine +octane, or +decane, or +dodecane, or +tetradecane and for 4-ethoxy-benzenamine +heptane, or +octane. The experimental method used is based on the observation, by mean of a laser scattering technique, of the turbidity produced on cooling when a second phase takes place. All the mixtures show an upper critical solution temperature, which increases with the alkane size. Dipolar interactions between like molecules become stronger in the sequence: 2-ethoxy-benzenamine < aniline <4-ethoxy-benzenamine. Data available in the literature suggest that this relative variation is also valid for alkane mixtures containing other substituted anilines or phenols, characterized by having a second polar group. The dependence of the UCST values with the molecular structure of the polar aromatic compound involved is shortly discussed in terms of intramolecular and steric effects. (C) 2018 Elsevier B.V. All rights reserved.