Solubility of Poly(vinylpyrrolidone) with Different Molecular Weights in Supercritical Carbon Dioxide

For studying the phase behavior of poly(vinylpyrrolidone) (PVP) with different molecular weights in supercritical carbon dioxide (SCCO2), the equilibrium solubilities of PVP with different molecular weights of 10000, 24000, and 58000, which were widely used as polymeric carriers in supercritical fluid impregnation technology, were measured in SCCO2 at temperatures of (313, 323, 333, and 343) K and in the pressure range of (9.0 to 18.0) MPa by the dynamic method. The effects of pressure, temperature, and molecular weight of solute on PVP solubility were investigated by comparing the solubility data in SCCO2, and it was found that the solubility of PVP in SCCO2 increased with pressure and temperature increasing for the same solute molecular weight and with the solute molecular weight decreasing at the same operational conditions. The solubility data of PVP in SCCO2 were correlated by five density-based semiempirical models (Chrastil, M-S-T, K-J, S-S, A-L), and satisfactory correlation results were achieved ...