Surfactants
are widely used in industrial applications associated
with several solvents. Therefore, it is worthy to know the nature
of the molecular interactions present in surfactants and cosurfactant
mixtures, whose thermodynamic and physical properties can provide
important information from an academic and industrial viewpoint. In
this work, density and viscosity data of binary mixtures of toluene
+ Igepal series (Igepal CO-520, Igepal CO-630, Igepal CO-720, or Igepal
CA-720) were experimentally determined within a range of temperature T = 293.15–333.15 K and at an atmospheric pressure
of 101.325 kPa. From these data, the following derivative properties
have been evaluated: excess molar volume, viscosity deviation, thermal
expansion coefficient, partial molar volume, and excess thermal expansion
coefficient. It was observed that all these mixtures showed the prevalence
of dispersion intermolecular forces.