Effect of chemical modification with 4-vinylpyridine on dyeing of cotton fabric with reactive dyestuff

Cotton fabrics were pre-treated with 4-vinylpyridine before dyeing to increase dye uptake. Various treatments for the application of monomers to fabrics were tried in different combinations and after dyeing the best result was obtained with alkali impregnation and monomer exhaustion. After decisions had been made on the processes to be applied before dyeing, different amounts of monomer, dyestuff and salt were used in reactive dyeing baths at different pHs. The results were evaluated in terms of color coordinates, color strength, FT-IR and fastness to washing, rubbing and perspiration. The best results were obtained with 3ml of 4-vinylpyridine dissolved in 10ml of alcohol, in the presence of 25g L-1 of salt and in neutral medium at 5% dyestuff concentration. Color strength from this dyeing process was higher than from the conventional dyeing at the same dyestuff concentration. FT-IR analysis demonstrated the presence of monomer on the surface of the fabric. Fastness values showed that this method could be used as an alternative to the conventional method.