Solubility comparison and partial molar volumes of 1,2-hexanediol before and after end-group modification by methyl oxalyl chloride and ethyl oxalyl monochloride in supercritical CO2

Bis(methoxy oxalic)-1,2-haxenediester and bis(ethoxy oxalic)-1,2-haxenediester were synthesized by modifying the end groups of 1,2-hexanediol with methyl oxalyl chloride and ethyl oxalyl monochloride. The solubilities of all three compounds in supercritical carbon dioxide were determined at different conditions of pressures (8.8 to 18.8) MPa and temperatures (313, 333, and 353) K. Then, the solubility data were correlated with the Bartle model and the Chrastil model. The average absolute relative deviation (AARD) for the Bartle model was in the range of (3.89 to 25.46)% which is within a good approximation. The Chrastil model also showed satisfactory agreement and the AARD was in the range of (3.70 to 16.92)%. Furthermore, the partial molar volumes of those compounds were estimated following the theory developed by Kumar and Johnston.

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► Two new “CO2-philic” compounds were designed and synthesized.
► The tested solubility data were calculated and correlated with two models.
► Satisfactory agreements were obtained between the tested and calculated data.
► The partial molar volumes V¯2 for three compounds were estimated.