Dyeing of Cotton in Supercritical Carbon Dioxide

Abstract The dyeing of cellulosic fibers with disperse and natural dyes was attempted using supercritical carbon dioxide (CO 2 SCF) as solvent system. The dye uptake was strongly increased if cotton was pretreated with polyethylene glycol (PEG), a known plasticizing agent of cellulose, while reasonable wet-washing and light fastness properties were achieved if PEG-treated cotton was dyed in CO 2 SCF with disperse dyes included in benzamide crystals. This might be a consequence of partial occlusion of cellulose pores by benzamide, forming hydrogen bonds with cotton and PEG.