Abstract

---

The main problem in dyeing cotton fabrics with reactive dyes is the low affinity of the fabrics for the dyes due to the negative charge acquired by the fabrics in aqueous medium which led to repulsion between the anion of the dye and the negative charge of fabrics. To overcome such repulsion, large amount of electrolyte is required to improve the affinity of the fabrics for reactive dyes. This leads to the discharge of highly coloured effluent with high salt content, which causes unavoidable threat to the environment. These problems can be overcome by modifying the surface properties of the cotton fabrics to improve its substantivity so as to develop salt free reactive dyeing. In this study, environment friendly approach of cationization of cotton using chitosan was employed. Dyeing properties of cotton fabrics treated with chitosan was compared with that of the untreated fabrics using FTIR spectral analysis. Dye exhaustion and the fastness was investigated using UVvisible spectrophotometric analysis. The results have shown improvement in dye exhaustion for chitosan treated fabrics in reactive dyeing in the absence of salts. The colour fastness properties of the treated fabrics were also improved compared to the untreated fabrics

Keywords: Cotton fabrics, Cationization, Chitosan, Dyeing and Reactive dyes.