New experimental
densities for diethylamine (DEA), dibutylamine
(DBA), and tributylamine (TBA) at 11 isotherms in the range of 293.15–473.15
K and 18 isobars up to 37.5 MPa are reported. PρT measurements (176 experimental data points) have been
performed using a high-pressure vibrating-tube densimeter. These data
were correlated with a new modified Tait-like equation considering
standard deviations of less than 2 × 10–4 g·cm–3, and then isothermal compressibility (κT) and thermal expansion coefficient (αP)
were calculated. This study is supported by the results of modeling
using the perturbed-chain statistical associating fluid theory (PC-SAFT).
The parameters of PC-SAFT equation of state (EoS), for pure solvents,
were rigorously determined by fitting the equation to the liquid PρT experimental data. In this study,
the correlations, which are based on minimizing the total objective
functions (density, pressure, and temperature) simultaneously, were
developed to estimate the PC-SAFT parameters. The model reasonably
predicted the behavior of PρT and the first- and second-derivative properties such as isothermal
compressibility (κT), thermal expansion coefficient
(αP), isobaric heat capacities (C
P), and speed of sound (u). The results
undoubtedly suggest that the model performance is enhanced for either
cases of the new modified Tamman–Tait equation and the PC-SAFT
EoS, based on employing the proposed parameters.