Adsorption Mechanism of Disperse Dye on Elastic Polyurethane Fibre

In this paper, the adsorption isotherms of two disperse dyes, C.I. Disperse Red 60 and C.I. Disperse orange 76, on two kinds of PU fibers at 90℃ were measured respectively. It was found that these adsorption isotherms followed a dual model, Nernst and Langmuir. Based on the parameters obtained in studying, the relationship between the chemical structure of dyes and their adsorption behaviors was arialyzed. Through the measurement of washing fastness of dyed sample with two dye concentrations, 1% （o.w. f） and 3% （o. w. f）, it was found that the pale shade dyeing possessed better wet-fastness than the dark. This phenomenon confirmed further that the disperse dyes were sorbed on the PU fiber by langmuir sorption and the partition mechanism.