Studies of viscosity and excess molar volume of binary mixtures: 3. 1-Alkanol+di-n-propylamine, and+di-n-butylamine mixtures at 303.15 and 313.15 K

The excess molar volume VE, the viscosity deviation Δη and the excess Gibbs energy of activation ΔG∗E of viscous flow have been investigated from density and viscosity measurements of 15 mixtures of ethanol, propanol, butanol, pentanol, heptanol, octanol and decanol with di-n-propylamine, and di-n-butylamine, and of hexanol with di-n-butylamine over the entire range of mole fractions at 303.15 and 313.15 K. The VE of all the systems are very large negative. Except for the ethanol with di-n-propylamine and di-n-butylamine mixtures, the magnitude of negative deviations in viscosity increases with chain length of alkanol. The results have been explained considering mixed association of alkanol with diamine through OH⋯N bond. The viscosity data have been correlated with the equations of Grunberg and Nissan, Tamura and Kurata, Hind, McLaughlin and Ubbelohde, Katti and Chaudhri, McAllister, Heric, and of Auslaender.