The present study aimed to evaluate the effect of temperature,
composition, and type of vegetable oil on the properties of mixture
hexane + vegetable oil. Experimental data of densities for mixtures
of vegetable oils (canola, soybean, and sunflower) with hexane were
measured at temperatures between 293.15 and 323.15 K in order to evaluate
the excess volume profiles of each system. Predictive and adjusted
equations were used to compare the results and evaluate models. The
thermodynamic properties of the mixture (excess Gibbs free energy,
entropy, and enthalpy (
G
ex,
S
ex,
and
H
ex, respectively))
were determined and evaluated. All volume profiles presented a negative
behavior, and the increase in this effect was observed when the temperature
was increased; also, it was noted that the most unsaturated vegetable
oils suffered a greater influence of temperature on their volumetric
profiles. Prediction models showed good agreement with the experimental
data of the literature. The
G
ex profiles presented a negative behavior in all cases,
while the
S
ex and
H
ex profiles were positive.
In general, large differences were not observed between the profiles
of
G
ex,
S
ex, and
H
ex for the studied mixtures of hexane
and vegetable oils.