This paper reports the experimental liquid–liquid equilibrium (LLE) data of seven acetic acid + alkane (C8–C14) binary systems with strong hydrogen bonding and cyclic dimer formation of acetic acid. These LLE data were measured up to the upper critical solution temperature by a cloud-point method using the laser-scattering technique. LLE behaviors of the systems acetic acid + alkane were compared to those in the systems acetonitrile + alkane, and the effects of acetic acid or acetonitrile on LLE behavior were examined from the perspective of hydrogen bonding or dimer formation. The experimental LLE data were successfully correlated by the nonrandom two-liquid (NRTL) model with two functional forms, the temperature-dependent parameters gij–gjj in the NRTL model. The regressed binary parameters in the NRTL model were proved to be thermodynamically valid through the Gibbs energy topological analysis based on the dimensionless Gibbs energy of mixing GM/RT.
Matsuda et al. (Tue,) studied this question.