Chapter 16 - Innovative approaches in the application of natural dyes on wool—Road to green coloration

Abstract

The chapter reviews the recent trends in dyeing of wool with natural dyes, and paves the way toward sustainability. An attempt has been made to investigate the possibility of wool dyeing with natural dye extracted from the Cinnamomum camphora middle-aged/mature leaves. Visually, a range of eco-friendly shades with quite different color gamut of varying hue and tone were produced via the application of different natural mordants. shells of onion (Allium cepa L.) have been used for the dyeing of the wool fabrics. Fermented dough extract (FDE) has been chosen as a natural mordant compound and the effect of pretreatment with the FDE is examined in terms of color strength and fastness values. It is observed that the pretreatment with FDE enhances not only the color strength of the dyed fabrics but also their brightness. An investigation on a novel coloring technique, based on laccase-mediated radical coupling of amino acid molecules of wool fibers, has been carried out. Response surface methodology was employed for optimization of natural dyeing of wool with henna leaves and yarrow flowers, by pretreatment with plasma. Wool yarn was treated with prepared chitosan-cyanuric chloride hybrid (Ch-Cy) and was checked for its capability to covalently react with wool, and its dyeing, color fastness, as well as antibacterial properties were also investigated. The studies considered improve dyeability, with enhanced properties and offer possible substitutes for existing chemicals that prove harmful and thereby contribute toward sustainability.