Dyeing of cotton in supercritical carbon dioxide

The dyeing of cellulosic fibers with disperse and natural dyes was attempte d using supercritical carbon dioxide (CO2SCF) as solvent system. The dye up take was strongly increased if cotton was pretreated with polyethylene glyc ol (PEG), a known plasticizing agent of cellulose, while reasonable wet-was hing and light fastness properties were achieved if PEG-treated cotton was dyed in CO2SCF with disperse dyes included in benzamide crystals. This migh t be a consequence of partial occlusion of cellulose pores by benzamide, fo rming hydrogen bonds with cotton and PEG. (C) 1998 Elsevier Science Ltd. Al l rights reserved.