High-pressure density measurements of poly(ethylene glycol) 600 [PEG600] saturated with carbon dioxide with an oscillating device of advanced accuracy

Abstract

Density measurements of poly(ethylene glycol) 600 (PEG600) and its mixture with carbon dioxide are presented for temperatures of up to 353 K and at pressures up to 40 MPa (PEG600) and up to 20 MPa (PEG600-CO2). The applied Anton Paar DMA HPM vibrating tube densimeter was calibrated using water, toluene, squalane, and glycerol. The averaged relative expanded uncertainty of the measurements is ± 0.63% for the pure PEG600 and the mixture’s measurements. A modified Tait equation was fitted to the pure PEG’s density results, which correlates well with literature values. The density of the equilibrated mixture with carbon dioxide as a function of pressure correlates well with other density trends of low molecular weight PEG mixtures reported in the literature. However, the absolute values are found to be lower than previously published results of the same fluid system.