초록 |
The impact of polymer backbone architecture on fluoropolymer solubility in supercritical fluid solvents is studied by systematically varying the chemical type of the repeat units in the main chain. A variable-volume view cell, capable of operating to high temperatures and high pressures, was designed and implemented to meet these extreme operating conditions. Cloud-point experimental data were presented at temperatures to 215 oC and pressures at 2,500 bar for poly(vinyl fluoride) and poly(vinylidene fluoride) in CO2, CHClF2, and dimethyl ether with ethanol, propanol, butanol, pentanol, heptanol and octanol. Poly(vinyl fluoride) does not dissolve in CO2 even at 215 oC and 2,500 bar, but poly(vinylidene fluoride) does dissolve in CHClF2 at 185 oC and pressures of 800 bar. To dissolve poly(vinylidene fluoride) in dimethyl ether, pressures in excess of 200 bar and temperatures in excess of 165 oC are needed.
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