Studies of viscosities of dilute solutions of alkylamines in non-electrolyte solvents: IV. Alkylamines in 1,4-dioxane and oxolane at 303.15 K

Abstract

Viscosities η 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 ( η − η S o ) / η S o and viscosity deviations Δ η have been calculated. The values of ( η − η S o ) / η S o and Δ η 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 Δ 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 ν 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.