Excess molar volumes and viscosities of binary mixtures of 2-butoxyethanol (butyl cellosolve) with chloroalkanes at 298.15 K

Molar excess volumes (VE) and dynamic viscosities (η) have been measured for non-electrolyte mixtures of 2-butoxyethanol (butyl cellosolve) with dichloromethane, trichloromethane or tetrachloromethane at 298.15 K over the whole concentration range. The excess volume curves are sigmoid with a maximum in the chloroalkane-rich region. From the experimental data excess viscosities (ΔElnη) and excess energies of activation for viscous flow (ΔG∗E) have been derived. These values are positive over the entire range of composition for the system 2-butoxyethanol + trichloromethane and change sign from negative to positive for the remaining systems, 2-butoxyethanol + dichloromethane and + tetrachloromethane. The results for VE, ΔElnη and ΔG∗E are discussed in terms of the interaction between components. The Flory theory of mixtures provides a useful basis for a qualitative interpretation of the results.