Experimental validation on the phase separation for the 2-(Diisopropylamino)ethyl methacrylate and Poly[2-(diisopropylamino)ethyl methacrylate] in supercritical CO2

Abstract

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 (propylene, 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.