Modeling the Partitioning of Oligomers in Supercritical CO2

The solubility of polymers of various chain length in supercritical CO2 is investigated using the Sanchez-Lacombe equation of state. Four different systems, characterized by largely different solubilities in supercritical CO2, are considered, and the results are compared to experimental data. After applying some simplifying assumptions that have already been proposed in the literature, a new scaling procedure of the Sanchez-Lacombe pure component parameters is introduced. A satisfactory description of the experimental partition coefficients is obtained when fitting the interaction parameters as a function of chain length.