Salt-free reactive dyeing of the cotton fabric modified with chitosan-poly(propylene imine) dendrimer hybrid

Abstract

Cotton fabric was successfully modified by chitosan-poly(propylene imine) dendrimer hybrid (CS-PPI). Cationization of cotton was conformed through zeta potential test. The effects of grafting variables, CS-PPI concentration, pH, time, and temperature on grafting yield were investigated using both salt-free and conventional reactive dyeing processes. Optimal grafting parameters were found to be CS-PPI concentration of 20 % owf, pH 6, grafting reaction temperature of 50 °C, and time of 18 h. Color strength of dyed modified cotton was markedly enhanced in absence of electrolyte or alkali. Dye build-up of modified cotton in salt-free dyeing was higher than that of raw cotton dyed by conventional method. Moreover, the amount of dye fixed on modified cotton was markedly higher than that of virgin cotton. Wash, light, and rubbing fastness and mechanical properties of dyed modified cotton were satisfactory. The results clearly demonstrated high potential of CS-PPI hybrid as a promising bio-compatible compound for eco-benign modification and salt free reactive dyeing of cotton fabrics with satisfactory properties.