Waterless dyeing of polytrimethylene terephthalate and polybutylene terephthalate fabrics via supercritical carbon dioxide

In this study, polytrimethylene terephthalate (PTT) and polybutylene terephthalate (PBT) samples were dyed n supercritical carbon dioxide (scCO2) medium. Dianix Dry Blue XF2 and CI Disperse Blue 79 were used for dyeing. Pressure and time optimisation trials were conducted, maintaining the temperature constant based on the optimal results obtained from these trials. The color, fastness, and tensile strength values were assessed. For both PTT and PBT fabrics, the closest color values to conventional dyeing were achieved when dyed with CI Disperse Blue 79 at 85 degrees C and 25 MPa, and with Dianix Dry Blue XF2 at 70 degrees C and 25 MPa. Notably, when compared to conventionally dyes samples, darker colors were obtained in scCO2 medium after 70 degrees C when dyeing with Dianix Dry Blue XF2 and after 85 degrees C when dyeing with CI Disperse Blue 79 compared to conventionally dyed samples.