Pressure-volume-temperature properties for binary oligomeric blends of polyethylene glycol mono-laurate with polyethylene glycol mono-4-octylphenyl ether or polyethylene glycol mono-4-nonylphenyl ether at pressures up to 50 MPa

Densities are measured for two binary systems of oligomeric blends, polyethylene glycol mono-4-octylphenyl ether) (PEGOPE) + polyethylene glycol mono-laurate (PEGML) and polyethylene glycol mono-4-nonylphenyl ether (PEGNPE) + PEGML, at temperatures from 298.15 K to 348.15 K and pressures up to 50 MPa. The excess volumes are negative for these two binary systems over the majority of composition range, except for the regions near pure components, in which the values may change into positive. Tait equation represents accurately for the pressure-effect on the liquid densities. Additionally, a generalized equation with two characteristic parameters correlates well the P-V-T data over the entire experimental conditions for each binary system. Those P-V-T data are also correlated satisfactorily with the Flory-Orwoll-Vrij (FOV) and the Schotte equations of state with one binary interaction parameter for each oligomeric blend system.