Relationships between the solubility of C. I. Disperse red 60 and uptake on PET in supercritical CO2

The solubilities of C. I. disperse red 60 in supercritical CO2 at temperatures of 353 K, 373 K, and 393 K and pressures from 11 MPa to 23 MPa were determined. The results showed that within the range of the experiments the solubilities remained at a magnitude of 10-6 mol dye/mol CO2 and were increasing with increasing pressure or density at constant temperature. The equilibrium solubility data were successfully correlated using a semiempirical model. To reveal the relationships between dye solubility and its uptake on the fiber, we carried out dyeings of PET fiber in supercritical CO2 at corresponding pressures and temperatures. The results showed that very high solubility was not beneficial for high dye uptake because the dyeing of PET in SC-CO2 also obeyed the partition rule as in water.