Thermodynamics of branched alcohols I. Extension of DISQUAC to tert-alcohols-n-alkanes or tert-alcohols-cyclohexane mixtures

DISQUAC interchange coefficients for the contacts tertiary OH-aliphatic and tertiary OHcyclohexane are reported. The quasichemical parameters are independent of the alkane; the first and third quasichemical parameters are common for the alkanols investigated, whereas the second depends on the position of the OH group. Therefore, two ensembles of alcohols are distinguished: 2-methyl-2-alkanols and 3-methyl-3-alkanols. Tert-butanol behaves differently owing to its high melting point. Dispersive parameters change with the alcohol. This behaviour is compared with that observed for other contacts. Vapor-liquid equilibria and excess functions, even the excess heat capacity, are well represented by the model. In contrast, partial molar excess quantities at infinite dilution are poorly described.