Kinematic Viscosity and Refractive Index of Aqueous Solutions of Ethanol and Glycerol

The kinematic viscosity of ternary solutions of glycerol/ethanol/water was determined at several temperatures (from 20 to 45 degrees C) and different molar fractions of the components (to 0.75 for ethanol and 0.60 for glycerol) covering a wide range of experimental conditions. A capillary viscometer was used for the measurements. The experimental kinematic viscosity data showed nonideal behavior. Modeling was based on previously proposed correlations for aqueous ethanol solutions modified with an additional exponential term in which the influence of glycerol is taken into account. The final model reproduced the experimental kinematic viscosity data of glycerol/ethanol/water solutions as a function of concentration and temperature with average deviations of 4.6% in the tested range. Refractive indices (at 20 degrees C) of the ternary solutions were also determined, and a empirical model was proposed to evaluate this physical property with high accuracy.