Dyeing Of Cotton Fabric With A Disperse-reactive Dye In Supercritical Carbon Dioxide

Dyeing of cotton fabric with a disperse-reactive dye in supercritical carbon dioxide was studied in this paper. The Uv-vis spectrophotometer, Connection in the dyeing equipment of supercritical carbon dioxide, was used to research the solubility of special activity dispersal red dye in supercritical carbon dioxide, and the influence of temperature, pressure and dissolving time on the dye solubility was investigated.Then, the dyeing property of special activity dispersal red dye in supercritical carbon dioxide on cotton fiber was researched, and the technological parameters of dyeing, such as temperature of supercritical carbon dioxide, pressure and dyeing time, were investigated. Furthermore, the fixing auxiliaries with good solubility in supercritical carbon dioxide was appiled, and the catalytic fixing capability of dyes was studied.The effect of temperature, pressure, time and dosage of the f fixing auxiliaries on fixing efficiency and fixing rate of activity dispersal red dye was studied, and the dynamics of catalysis fixing of activity dispersal red dye on cotton fiber in supercritical carbon dioxide were investigated.In addition, the changes of cotton structure treating with supercritical carbon dioxide were showed by scanning electron microscope (SEM),FT-IR spectra, X-ray diffraction (XRD) and so on.The result proved that, the dye solubility was increased with increasing pressure and temperature in supercritical carbon dioxide, and the dye solubility gradually achieved the balance with the extension of time.On the basis of difference in dyeing percentage on cotton in various dyeing conditions, the proper dyeing condition was confirmed as80℃×23MPa×2h. When the fixing condition was140℃×6MPaxlh, with1.44g triethylene diamine, the fixing effect of activity dispersal red dye on cotton was fine.Dyeing dynamics showed that reaction rate constant of dye molecule in the conventional dyeing was bigger than in supercritical carbon dioxide, and reaction rate constant of dye molecule increased with the addition of fixing auxiliaries.After treating in supercritical carbon dioxide, the surface structure of cotton fiber had some nick and groove, and the stretching vibrational peak of hydroxy group (O-H) on cellulose I of cotton was slightly offset. Moreover, the degree of crystallization、crystal size of cotton fiber and the heat resistant performance of cotton had a little change.