Excess molar enthalpies of binary mixtures containing 2-decanone or dipentyl ether with long-chain n-alkanes at T = 298.15 K

Excess molar enthalpies (HE) of binary mixtures of 2-decanone or dipentyl ether with n-alkanes, including n-dodecane, n-tetradecane, and n-hexadecane, were measured with an isothermal titration calorimeter (ITC) at T = 298.15 K under atmospheric pressure. All the measured HE values are positive over the entire range of composition, indicating that all these mixing processes are endothermic. The HE values varying with composition are found to be nearly symmetric for each binary system. It was also shown that the HE values follow the order of n-hexadecane > n-tetradecane > n-dodecane at a given composition in either the 2-decanone or dipentyl ether binary systems. An empirical Redlich–Kister equation correlated quantitatively these new HE data. The Peng–Robinson and the Patel–Teja equations of state, and the NRTL model were also applied to fit the HE results. Among these tested correlative models, the Patel–Teja equation of state with two adjustable binary interaction parameters generally yielded the best representation.

Research highlights
► An isothermal titration calorimeter was used for enthalpy data measurment.
► The investigated systems are 2-decanone or dipentyl ether with long-chain n-alkanes.
► The excess enthalpies are all positive over entire composition range.
► The Patel-Teja equation of state with two parameters gives the best representation.