Synthesis and efficient dyeing of anthraquinone derivatives on polyester fabric with supercritical carbon dioxide

Two series of anthraquinone dye derivatives [CNU-1 to CNU-7 and CNU-8 to CNU-10] have been successfully synthesized from commercially inexpensive and readily available starting materials by using simple and convenient methods. All synthesized anthraquinone dyes were characterized by H-1 NMR, C-13 NMR, and UV-Vis spectroscopy and HRMS. The UV-Vis spectra of the dyes indicated that the absorption wavelengths of dyes were approximately 590-655 nm, which indicated that these are blue dyes. Polyester fabrics were dyed with these compounds using supercritical carbon dioxide as a green medium. All the compounds displayed deep color shades and excellent dye fixation even at low concentrations (0.5%). In the fastness experiments, compounds CNU-1 to CNU-10 all exhibited excellent results in washing (4-5), sweat (4-5) and lightfastness [CNU-1 to 7 (4-5), CNU-8 to 10 (2-3)]. Hence, our results revealed that these types of anthraquinone dyes are commercially most acceptable, and they practically exhibited satisfactory color uniformity.