High-pressure phase equilibrium data for the ternary and quaternary systems containing carbon dioxide, globalide, e-caprolactone dichloromethane

Polymers, both natural and synthetic, are present in many areas of modern society. The majority of these polymers, however, are made from petroleum-derived monomers, a non-renewable source that produces pollutants. In this way, it is necessary to search for biodegradable polymers that do not generate pollutants both in production and disposal. The use of supercritical carbon dioxide (scCO2), replacing organic solvents, has shown to be a green alternative to traditional polymerization processes. This work reports experimental phase equilibrium data for the ternary system involving carbon dioxide, globalide and e-caprolactone and quaternary system containing carbon dioxide, dichloromethane, globalide and e-caprolactone, which are fundamental information to conduct polymerization reactions in supercritical carbon dioxide medium. The experiments were performed using a variable-volume view cell over the temperature range from 313.15 to 343.15 K, and different molar fractions of carbon dioxide in relation to monomers (globalide + e-caprolactone) for ternary system and different mass ratios of dichloromethane to monomers (globalide + e-caprolactone) (0.5:1, 1:1) for quaternary system. Phase transitions of vapor-liquid equilibrium at the bubble point (VLE-PB) and dew point (VLE-DP) were observed. The mass ratio of 1:1 (globalide to caprolactone) was kept constant for all systems. The PR-vdW2 model with a global temperature fitting approach was employed to predict the phase equilibrium behavior for the ternary and quaternary systems and the thermodynamic model was able to properly correlate the phase equilibrium transition.

Automated summary

Polymers, which are widely used in modern society, are mainly made from non-renewable petroleum-derived monomers, resulting in pollution. Therefore, it is important to find biodegradable polymers that can be produced and disposed of without generating pollutants. The use of supercritical carbon dioxide instead of organic solvents has shown to be a greener alternative for polymerization processes.