Reactive dyes in today's scenario

摘要

Almost after a century of the synthesis of the first artificial dye reactive dyes were made. Before the advent of reactive dyes the coloration of cotton was achieved by direct, vat, azoic, sulphur, solubilised vat, solubilised sulphur, and basic dyes (after mordanting). In all these cases dyes were held onto the fibres by different attractive forces like H-bonding, electrostatic or the colored molecules were trapped into the interstices of the cotton. The possibility of attaching dyes with fibres with a covalent bond has long been attractive to dyestuff chemists because attachment of dye molecules to the fibres by physical adsorption and mechanical retention have the disadvantages of high cost, low wet fastness and elaborate dyeing methods (except direct dyes).