Dyeing Characteristics of Polypropylene Fabric Dyed with Special Disperse Dyes Using Supercritical Carbon Dioxide

Using disperse dyes of different colors and hues to produce a variety of shades is necessary for the industrialization of supercritical fluid dyeing of polypropylene. Eight derivatives of 3-(3-chlorophenyl)-1-phenyl-4-(diazenyl derivatives)-1H-pyrazol-5-amine dye were synthesized explicitly for use in supercritical carbon dioxide medium. Polypropylene dyeing was studied in supercritical carbon dioxide under varying conditions: Dyeing temperatures ranged from 100 °C to 120 °C, dying times ranged from 1 h to 2 h, concentrations ranged from 2% owf (on the weight of fabric) to 4%, and pressures ranged from 15 to 25 MPa. Significant improvement of the colorfastness to washing and rubbing was observed. Raman spectroscopy was performed and showed conclusively that the dye was absorbed within all layers of polypropylene. This study achieved the elimination of water and its costly processing in the dyeing of synthetic fabrics.