Kinetic and thermodynamic analysis study of the dyeing process of acrylic fabrics with basic dyes in presence of organic solvents

Abstract

Kinetic and thermodynamic analysis of the dyeing process of acrylic fibers (Orlon) with basic dyes in the presence of small amounts of the solvents benzyl alcohol, butanol and 1-4 Dioxane are described in the present work. The dyeing affinity was measured using Gilbert and Rideal?s equation. Results show a close affinity on dye structure. The effect of increasing the dyeing temperatures from 80 to 95 oC as well as increasing the dyeing time over a range from 10 minutes to180 minutes was studied. Changes of enthalpy and entropy related to the process of absorption are calculated. The best thermodynamic conditions for dye uptake by acrylic fibers appear at the highest temperatures, when the standard free energy of absorption takes the most positive values. The mechanism of dye interaction with the fiber has been briefly considered. From the results, we find that the absorption of dye by acrylic fibers in the temperature interval investigated takes place with establishment of chemical bonds, although physical contributions of electrostatic nature between both the dye and the available sites in the fiber.