Enhancement of the viscosity of carbon dioxide using styrene/fluoroacrylate copolymers

Copolymers of a fluorinated acrylate and styrene were synthesized to enhanc e the viscosity of liquid carbon dioxide. The phase behavior of mixtures of these polymers with carbon dioxide was measured at 295 K and pressures fro m 6.70 to 48.28 MPa. Miscibility pressures decreased with a decrease in the styrene content and increased as molecular weight increased. These polymer s were also found to significantly Enhance the viscosity of carbon dioxide, by a factor of ca. 5 to 400 at concentrations from 1 to 5 wt %. The optima l composition for viscosity enhancement was 29 mol % styrene-71 mol % fluor oacrylate.