Solution thermodynamics of tris-(2,4-ditert-butylphenyl)-phosphite in a series of pure solvents

In this work, to help the development and design of separation and purification processes for tris-(2,4-ditert-butylphenyl)-phosphite which is an antioxidant of plastic processing, its solution thermodynamics was investigated. Using a static gravimetric method, solubilities of tris-(2,4-ditert-butylphenyl)-phosphite in twelve pure solvents (including acetone, ethyl acetate, methyl acetate, ethyl formate, isopropyl acetate, butyl acetate, n-hexane, n-heptane, n-octane, isooctane, propyl acetate and ethyl butyrate) were measured at temperatures varying from 278.15 K to 323.15 K. It was found that, in all investigated solvents, the solubility data of tris-(2,4-ditert-butylphenyl)-phosphite increased with the increasing of temperature over the entire investigated temperature range. The modified Apelblat equation, the λh equation and the NRTL model were employed to correlate the solubility data. The computed data showed that the modified Apelblat equation correlated the solubility data better. Moreover, the mixing and dissolution thermodynamic properties of tris-(2,4-ditert-butylphenyl)-phosphite in various pure solvents were also calculated according to the NRTL model and the experimental solubility data.