Measurement and modeling of poly(vinyl stearate) in supercritical fluids

• Published in: Journal of CO2 utilization 2020-04, Vol.37, p.346-352
• Main Authors: Kim, Yong-Soo, Yeo, Woon-Hong, Lee, Bong-Seop, Byun, Hun-Soo
• Format: Article
• Language: English
• Subjects: Carbon dioxide; Cloud-point; PC-SAFT; Poly(vinyl stearate); Supercritical fluid
• ISSN: 2212-9820; 2212-9839
• DOI: 10.1016/j.jcou.2020.02.011

[Display omitted] •At a fixed T and P, the cloud-points were measured for PVS in several supercritical fluids.•The measured cloud-point pressures for all systems show a LCST-type phase behavior.•The PC-SAFT model is applied to correlate and predict the solubility of PVS.•The strong interactions between PVS and CO2 leads to higher solubility of PVS in CO2/DME mixture.•The weak cross-interactions between CO2 and co-solvent result in the increase of the solubility of PVS in their mixtures. The cloud-points (CPs) of poly(vinyl stearate) (PVS) in several fluids, such as carbon dioxide (CO2), propane, butane, propylene, 1-butene, and dimethyl ether (DME), and in their mixtures are reported herein. A high-pressure apparatus with a variable-volume view cell was used to measure the CPs of the PVS mixtures. The measured CP pressures for all the systems exhibited a lower critical solution temperature (LCST) phase behavior. The CPs for ternary systems consisting of CO2, DME, propylene, 1-butene, and PVS were distributed over the temperature range of 333−453 K and the pressure range of 35−203 MPa. To understand the effect of interactions between the solvents, co-solvents, and PVS at a molecular level, the perturbed-chain statistical associating fluids theory (PC-SAFT) model was applied to the modeling of these systems, and the predicted results were observed to be consistent with the tendency of experimental data. A theoretical investigation using the PC-SAFT model revealed some important information. The strong interactions between PVS and CO2 resulted in the high solubility of PVS in the CO2/DME mixture, while the weak interactions between CO2 and the co-solvent (i.e., propylene, 1-butene) increased the solubility of PVS in their mixtures.