Synthesis and Measurement of Solubilities of Reactive Disperse Dyes for Dyeing Cotton Fabrics in Supercritical Carbon Dioxide

Solubilities of the reactive disperse dyes synthesized with the reactive group of 1,3,5-trichloro-2,4,6-triazine were investigated in supercritical carbon dioxide (SC-CO2) at pressures of 10.025.0 MPa, temperatures of 333.2393.2 K, and equilibrium contact time of 60 min. Meanwhile, dyeing experiments of cotton fabrics by using these dyes were performed at 373.2 K and 20.0 MPa for 60 min with a dye concentration of 0.5% owf in SC-CO2. Solubilities of these dyes increased with increasing pressure and decreasing temperature. Additionally, the color strength and the color fastness of dyed cotton fabrics were measured, and reasonably good dyeing effects were obtained. Furthermore, the color characteristics of dyed cotton fabrics were studied in terms of the reflectance spectra, and their surface morphologies were investigated by SEM as well.