Thermodynamics of solvent extraction processes: Heat capacities, heats of mixing and solution of organophosphorus extractants in dodecane

Abstract

Excess enthalpies of mixing of tributylphosphate and dibutylbutylphosphonate with n-dodecane have been measured calorimetrically at 293.15, 303.15 and 313.15 K. From the data at low extractant concentrations, the standard heats of solution at infinite dilution, heats of solvation and heat capacities for the solution process have been derived. The various data indicate that the self-association of the esters is likely to play an important role in the thermodynamic properties of the mixtures.