Use of the β-Cyclodextrin Additive as a Good Alternative for the Substitution of Environmentally Harmful Additives in Industrial Dyeing Processes

Abstract

In this work, the substitution of environmentally harmful additives in the industrial dyeing process of polyamide-6 microfiber-made knitted fabrics (PA-6µFKF) was studied. Using the disperse red 60 (DR60) dye, kinetic adsorption tests on the PA-6µFKF dyeing were performed by using either β-cyclodextrin (β-CD) additive, commercial leveling agents, or without additives. Equilibrium tests were also performed during 25 h. A modelling based on a dye adsorption process controlled by an intraparticle diffusion was proposed to represent the sets of kinetic data. Three isotherm models were also tested for representing the equilibrium data. The kinetic data have evidenced three main dye diffusion zones. Different adsorption mechanisms on PA-6µFKF surface dyeing was evidenced, being the data well represented by the two-step Langmuir isotherm. Finally, the best quality on color uniformity was attained using the β-CD additive, revealing a good alternative for the substitution of environmentally harmful additives in industrial dyeing processes.