| Compared with traditional dyeing technology, supercritical carbon dioxide dyeing is an innovative method to reduce waste discharge and need even less time with desired dyeing effect. For further development of the above research field, solubility data of dyes in supercritical fluid are required.Two apparatus, continuous flow and circulated batch, were used to measure four disperse dyes in supercritical carbon dioxide. The solubilities of disperse yellow 119, disperse red 343 measured by continuous flow method and disperse orange 30, disperse orange 31 measured by circulated batch method were in the range of 1.6×10-8-1.9× 10-7, 3.8×10-9-3.5× 10-6, 2.1×10-5-7.8×10-5 and 1.4×10-5-3.7×10-5, respectively. Circulated batch method is better than continuous flow method to evaluate dye solubility in supercritical fluid.The experimental results showed the solubilities increased dramatically with the rise of pressure at constant temperature, while the solubilities behavior with temperature is more complex. The solubilities of disperse yellow 119 and disperse red 343 decreased with increasing temperature below a change pressure. On the other hand, it increased with increasing temperature above a change pressure. The solubility of disperse orange 30 and disperse orange 31 increased with the increasing temperatureat constant pressure.As the experimental results suggested that the dyes contain -OHn -NO2 groups associate and interact with each other and form a large molecule, resulting in lower solubilities, while -Cl groups has a beneficial effect on the solubilities.The equilibrium solubility data were correlated with the Chrastil eqution and Peng-Robinson(Pi?) equation. The results calculated by the Chrastil eqution showed better agreement with the experimental data than the PR equation.The partition coefficients (K^) of disperse yellow 119 between polymer phase and supercritical carbon dioxide phase were measured in this paper. Keq increased with the increasing of the temperature and decreased with the increasing of the pressure.
|
PDF Full Text Request