Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

ABSTRACT

A series of diglycolic acid esters, potent CO2-philic chelating agents, were designed and synthesized. The solubilities of these compounds in supercritical CO2 were determined at temperatures from (313 to 333) K and pressures from (8.6 to 20.4) MPa. All of the synthesized esters showed good to high solubility (as high as 1.6*10-2 mol*L-1 for compound 1 at 9.3 MPa and 313 K) in supercritical CO2 at easily accessible temperatures and pressures. To confirm the tested solubility, two density-based correlations proposed by Bartle and Chrastil were investigated for the seven glycolic acid esters.The results showed good self-consistency of the data calculated by the Bartle semiempirical equation and differed from the measured values by between (4 and 37) %. Better agreement with experimental solubility data is obtained with the Chrastil model, and values of AARD lower than 11 % were observed. Solubility data were also used to estimate the partial molar volume 2 for each diglycolic acid ester in the supercritical phase using the theory developed by Kumar and Johnston.