Novel CO{sub 2}-thickeners for improved mobility control

The objective of this study was to design, synthesize, and characterize thickening agents for dense carbon dioxide and to evaluate their solubility and viscosity-enhancing potential in CO{sub 2}. Previously, hydrocarbon-fluorocarbon random copolymers, sulfated hydrocarbon-fluorocarbon random copolymers, semifluorinated trialkyltin fluorides and small hydrogen-bonding compounds were evaluated. Random copolymers of styrene and heptadecafluorodecyl acrylate yielded substantial increases in viscosity. The amount of styrene varied between 22--40 mole% in the copolymer. Falling cylinder viscometry results indicated that the 29% styrene--71% fluoroacrylate copolymer induced (at 295K and 34.5 Mpa) increases of 10, 60 and 250 at copolymer concentrations of 1, 3 and 5wt%, respectively