Solubilities of Diglycolic Acid Esters in Supercritical Carbon Dioxide

A series of new CO2-soluble diglycolic acid esters were designed and synthesized, and their structures were confirmed by IR, NMR, and elemental analysis. The solubilities of compounds were measured at temperatures ranging from (313 to 333) K and pressures from (8.5 to 19.3) MPa in supercritical carbon dioxide. All of the newly synthesized esters showed good to high solubility (as high as 1.25 mol % for compound 1) in supercritical CO2 at easily accessible temperatures and pressures. The measured solubility data were correlated using a semiempirical model. Consequently, the calculated results showed satisfactory agreement with the experimental data and differed from the measured values by between (3.18 and 19.58) %.