Salt-free reactive dyeing of cotton fabric modified with HBP-NH_2 agent

The self-made amino-terminated hyperbranched polymer(HBP-NH2) was applied to modify cotton fabric in order to achieve salt-free dyeing with reactive dyes.The surface ζ-potential in water solution,dyeing thermodynamics and kinetics with reactive dyestuffs and hue changes of the modified cotton fabrics were examined.Results showed that the ζ-potential in water solution was positive at pH value below 7.5.The dyeing behaviors of Reactive Brilliant Yellow A-4GLN on treated cotton fabric were found to follow Langmuir-type adsorption curve,adsorption constant(K) and saturated adsorbing capacity(S) decreased along with the increase in temperature,the dyeing entropy(ΔH) was-4.59 kJ/mol.HBP-NH2 modification can impart cotton fabric better dyeing rate,equilibrium dye uptake and diffusion coefficients,while lead to a slight hue changes with reactive dyestuffs.