Thermodynamics Research Center / ThermoML | Fluid Phase Equilibria

ABSTRACT

Cloud-point behaviors at pressure up to 230 MPa and temperatures up to 463 K were measured for poly(2-dimethylaminoethyl methacrylate) [P(2-DMAEMA)] in CO2(carbon dioxide), C3H8(propane),C3H6(propylene), C4H10(butane), C4H8(1-butene), and CH3OCH3[dimethyl ether (DME)], as well asfor the P(2-DMAEMA) + 2-dimethylaminiethyl methacrylate (2-DMAEMA) (or DME) in supercritical CO2.The phase behavior for the P(2-DMAEMA) + CO2+ 2-DMAEMA mixture was measured in changes of the pressure-temperature (p, T) slope and with 2-DMAEMA mass fraction of 0.0 wt%, 5.5 wt%, 11.6 wt%,21.2 wt% and 48.1 wt%. With 51.4 wt% and 60.4 wt% 2-DMAEMA to the P(2-DMAEMA) + CO2solution, the cloud point curves take on the appearance of a typical lower critical solution temperature (LCST) boundary, liquid + liquid transition and liquid + vapor transition. The cloud point curves for theP(2-DMAEMA) + CO2+ (0.0 95.0) wt% DME systems change the (p, T) curve from upper critical solution temperature region to lower critical solution temperature region as the DME mass fraction increases. The phase behavior curves for P(2-DMAEMA) in alkane hydrocarbons were about 50 to 60 K higher thanP(2-DMAEMA) + alkene hydrocarbons curves, at a fixed pressure of about 70.0 MPa. Also, the impact by 2-DMAEMA and DME mass fraction for the P(2-DMAEMA) + propane + 2-DMAEMA + DME system was measured at temperatures to about 453 K and a pressure range of 4.3 to 192.9 MPa.The experimental data was presented for the CO2+ 2-DMAEMA system at temperatures ranging from313.2 to 393.2 K and pressures up to 19.07 MPa. The CO2+ 2-DMAEMA system exhibits type-I phasebehavior with a continuous critical mixture curve and was correlated with Peng-Robinson equation ofstate using a van der Waals one-fluid mixing rule including two adjustable parameters. The property of2-DMAEMA was obtained by Constantinou-Gani group contribution method.