Reflectance spectroscopic optimization of dyeing process and color characterization of ammonia post‐treated wool dyed with Tectona grandis L. leaves extract

Abstract

Anthraquinones based natural dyes are known to form stable complexes with metal ions and the resultant metal‐dye complexes are characterized by good fastness to light and have been extensively studied due to their great potential in the field of functional textiles. To the best of our knowledge, this work investigated for the first time combined effect of potassium aluminium sulfate premordanting and ammonia after‐treatment on dyeing potential, colorimetric characteristics (CIEL*a*b* and K/S), and fastness properties of anthraquinone natural dye extracted from waste leaves of Tectona grandis L. on wool. The dyeing process variables such pH, temperature, and time were optimized through conventional one‐factor‐at‐a‐time (OFT) optimization technique using reflectance spectroscopic method. The optimum conditions for best dyeing results were found to be –dyebath pH 4: dyeing temperature of about 70°C, and a dyeing time of about 90 min. The premordant dyeing with Al3+ and post‐treatment with ammonia yielded different colors with acceptable color fastness to washing, rubbing and good color fastness to light. © 2018 American Institute of Chemical Engineers Environ Prog, 37: 1901–1907, 2018