Dyeing of natural fibres from perfluoro‐polyether reverse micelles in supercritical carbon dioxide

The dyeing of natural fibres from a reverse‐micellar system in supercritical carbon dioxide has been investigated using ammonium carboxylate perfluoropolyether as surfactant. Protein fibres such as silk and wool were satisfactorily dyed in deep shades with conventional acid dyes without special pretreatment. Exhaustion was excellent. It was however found that on these fibres the performance of acid dyes was strongly influenced by temperature and carbon dioxide density. Conventional reactive dyes in this system were adsorbed on cotton, even in the absence of dyeing auxiliaries, but the fixation of the dye was not satisfactory. Compared with supercritical dyeing methods reported previously, it was found in this study that the temperature and pressure required were significantly lower.