High pressure phase behavior of ternary system (carbon dioxide plus globalide plus dichloromethane) at different dichloromethane to globalide mass ratios

Globalide is a 16-membered macrolactone, which contains a double bond, typically used in the fragrance industry, due to its musky odor. However, its application as a monomer for the synthesis of the polyester polyglobalide (PGl) is drawing attention of the scientific community, due to its biocompatible and non-toxic character, being a great candidate for biomedical applications. This kind of polymer are frequently synthesized using green solvents, and pressurized carbon dioxide is being reported as a suitable alternative in polymerization processes. In this work, we evaluate the phase behavior of the ternary system carbon dioxide (1) + globalide (2) + dichloromethane (3), at high pressures. Experimental measurements of the phase equilibrium of the system were carried out at the following dichloromethane/globalide mass ratios: 0.5:1, 1:1 and 2:1, in a range of temperatures varying from 313 to 343 K. Thermodynamic modeling of the experimental data was performed using Peng Robinson equation of state with van der Waals biparametric quadratic mixing rule (PR-vdW2). Phase transitions of vapor-liquid (bubble point), liquid-liquid and vapor-liquid-liquid types were observed. The system showed LCST behavior (Lower Critical Solution Temperature), whose temperature increase results in higher pressures necessary for complete solubilization of the system. Dichloromethane showed to be an effective cosolvent, reducing the pressure required for the solubilization of the system. PR-vdW2 equation satisfactorily represented the system, with acceptable deviations under the studied conditions.

Automated summary

Globalide is a compound commonly used in the fragrance industry, but its application as a monomer for biomedical applications has attracted attention in the scientific community. In this study, we evaluated the phase behavior of a ternary system containing carbon dioxide and dichloromethane under high pressures. It was found that dichloromethane can effectively reduce the solubilization pressure of the system as a co-solvent. Thermodynamic modeling using the Peng Robinson equation with van der Waals biparametric quadratic mixing rule showed satisfactory agreement with the experimental data.