LAUSR

A novel disperse azo dye for dyeing polyester and nylon 6 fabrics in supercritical carbon dioxide (scCO2) fluid has been synthesized. 3-cyano acetyl indol was used as the starting material, which reacted with aryl/heteroaryl diazonium salts to afford arylhydrazonopropanenitriles. The newly synthesized compounds were characterized by elemental analysis, IR and 1H-NMR spectroscopy, and the results were observed to be in good agreement with the proposed structures. The influence of scCO2 working conditions, such as dyeing concentration, pressure, temperature, and dyeing time, on fabric color strength were studied. Moreover, the color strength was examined in detail. In addition, the position of color in CIELAB coordinates (L*, a*, b*, h*, C*) was assessed. The color fastness of the dyed samples provided excellent results. The ATR-FTIR results of the dyed samples were found to match the proposed structure.