THERMODYNAMIC ANALYSIS OF VISCOSITY DATA OF ETHANE-1,2-DIOL+1,4-DIOXAN BINARY-MIXTURES

Kinematic viscosities (nu) have been measured for pure ethane-1,2-diol, 1,4-dioxan and for nine of their mixtures covering the entire composition range and, where possible, at 19 temperatures from -10 to +80-degrees-C. The experimental values were converted into dynamic viscosities (eta) and were correlated with temperature and binary composition by some empirical equations. Furthermore, the excess function eta(E) and the excess Gibbs energy of activation of viscous flow DELTAG*E have been evaluated. Negative deviations from ideality are always observed for this binary system, this fact indicating strong specific interactions between unlike entities in solution to form stable solvent-cosolvent adducts. Activation enthalpies and entropies for viscous flow have been derived, and their dependence on binary composition is also discussed.