Experimental Validation on the Phase Separation for the 2-(Diisopropylamino)ethyl Methacrylate and Poly[2-(diisopropylamino)ethyl Methacrylate] in Supercritical CO2

Using an intense pressure flexible volume apparatus, the phase transition equilibrium of the two-component mixture consisting of 2-(diisopropylamino)ethyl methacrylate (2DIPAEMA) + supercritical carbon dioxide (Sc CO2), as well as poly(2-(diisopropylamino)ethyl methacrylate) [P(2DIPAEMA)] with various co-solvents (pro-pylene, propane, 1-butene, butane, and dimethyl ether), was investigated. Additionally, the three-component system P(2DIPAEMA) + 2DIPAEMA (0.0, 0.0245, 0.0523, 0.1036 mol fraction) + Sc CO2 was studied at a specific temperature range of 313.2 K to 454.5 K and an upper-pressure limit of 171.03 MPa. The dew-point, critical-point, and bubble-point equilibria data for the 2DIPAEMA + Sc CO2 binary system at a temperature interval of 313.2-393.2 K and a pressure limit of 21.61 MPa were measured. At low co-solvent concentrations, the solubility transition curve in the three-component P(2DIPAEMA) + Sc CO2 + co-solvent system (comprising propylene, propane, 1-butene, butane, and dimethyl ether) shows a cloud pressure curve that increases as temperature decreases. However, at higher concentrations, cloud pressure decreased rapidly, but a minor change in cloud pressure with temperature was recorded, indicating a homogeneous single-phase behavior resembling a type-I phase diagram. The van der Waals one-fluid mixing rule was employed to compare the experimentally calculated data with the computed and modelled data of the Peng-Robinson mathematical equation. It was discovered that the computed values were consistent with the experimental values. The RMSD for the (Sc CO2 + 2DIPAEMA) system was 4.37 % at five different temperatures. The critical parameter of the pure component, 2DIPAEMA, was estimated using the Joback-Lyderson approach.