Phase behavior of a ternary system of poly[p-perfluorooctyl-ethylene(oxy, thio, sulfonyl)methyl styrene] and poly[p-decyl(oxy, thio, sulfonyl)methyl styrene] in supercritical solvents

In this study, the high-pressure phase behavior of poly[p-decyl(oxy, thio, sulfonyl)methyl styrene] and poly[p-perfluorooctyl-ethylene(oxy, thio, sulfonyl)methyl styrene] in supercritical solvents comprised of carbon dioxide (CO2) and dimethyl ether (DME) were examined. When the poly[p-perfluorooctyl-ethylene(oxy, thio, sulfonyl)methyl styrene] + CO2 systems were evaluated, cloud-point pressures were obtained at temperatures ranging from 60 to 180 °C and pressures of up to 1300 bar. In addition, the poly[p-perfluorooctyl-ethylene(oxy, thio, sulfonyl)methyl styrene] + DME mixtures dissolved at temperatures under 180 °C and pressures under 200 bar, but the poly[p-decyl(oxy, thio, sulfonyl)methyl styrene] + CO2 mixtures did not dissolve, even at 230 °C and 2800 bar. However, the poly[p-decyl(oxy, thio, sulfonyl)methyl styrene] + DME mixtures readily dissolved at temperatures and pressures under 180 °C and 200 bar, respectively. Furthermore, the cloud-point curves for the poly(p-decyl sulfonyl methyl styrene) + DME mixtures with 15.6, 44.3 and 56.4 wt% CO2 changed the P–T curve from a lower critical solution temperature (LCST) type to an upper critical solution temperature (UCST) type at increased CO2 concentrations.

Graphical abstractThe high-pressure phase behavior of poly[p-decyl(oxy, thio, sulfonyl)methyl styrene] and poly[p-perfluorooctyl-ethylene(oxy, thio, sulfonyl)methyl styrene] in supercritical solvents comprised of CO2 and DME were measured using a variable volume view cell. The focus of this study is to determine the impact of substitution of the functional group (oxy, thio, sulfonyl) next to the styrene and the appearance when the connected alkyl group was changed to a perfluoro alkyl group by measuring the phase behavior of poly[p-perfluorooctyl-ethylene(oxy, thio, sulfonyl)methyl styrene] and poly[p-decyl(oxy, thio, sulfonyl)methyl styrene] in supercritical solvents, CO2 and/or DME. Figure optionsDownload full-size imageDownload as PowerPoint slide