Thermodynamics Research Center / ThermoML | Thermochimica Acta

ABSTRACT

Viscosities of dilute solutions of n-propylamine, n-butylamine, di-n-propylamine, di-n-butylamine, triethylamine, tri-n-propylamine, and tri-n-butylamine in 1,4-dioxane and oxolane (tetrahydrofuran) have been measured at 303.15 K. The specific viscosities ( - oS )/ oS and viscosity deviations have been calculated. The values of ( - oS )/ oS and for alkylamine solutions are negative in dioxane while positive in oxolane, and their magnitude increases with the increase in concentration of alkylamine. The values of excess Gibbs energy of activation G*E of viscous flow, based on Eyring s theory of absolute reaction rates, are negative for alkylamine solutions in 1,4-dioxane, while positive for alkylamine solutions in oxolane solutions. The results have been analyzed in terms of Herskovits and Kelly equation and Nakagawa equation. The values of viscosity increment in Herskovits and Kelly equation and the coefficient B int in Nakagawa equation are negative for the investigated alkylamine solutions in dioxane, while opposite is the case for oxolane.