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-butanol and 2-butanol at 303.15K have been measured. The specific viscosities ( - oS )/ oS and viscosity deviations have been calculated. The values of ( - oS )/ oS and are negative and their magnitude increases with the increase in concentration of alkylamine. The values of excess Gibbs energy of activation G*E of viscous flow determined based on Eyring s theory of absolute reaction rates are positive for alkylamine solutions in both the butanols. The strong solute solvent interactions leading to the structure formation between butanol and alkylamine molecules through H-bondings are observed. The results have been further analyzed in terms of Herskovits and Kelly equation and Nakagawa equation. The values of viscosity increment ( in Herskovits and Kelly equation and coefficient B int in Nakagawa equation are negative for all presently investigated alkylamine solutions.