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Enhancing the wash fastness of disperse dyes on wool with oxidants
Author(s) -
McNeil Steven J.,
Zaitseva Larissa I.
Publication year - 2020
Publication title -
coloration technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.297
H-Index - 49
eISSN - 1478-4408
pISSN - 1472-3581
DOI - 10.1111/cote.12453
Subject(s) - wool , dyeing , bleach , hydrogen peroxide , chemistry , melamine , anthraquinone , pulp and paper industry , ammonium , disperse dye , nuclear chemistry , organic chemistry , materials science , composite material , engineering
Disperse dyes are not currently applied to wool commercially, in large part because of inadequate wash fastness, but they do have potential, especially for wool‐polyester blends. In this study, for the first time hydrogen peroxide was investigated to increase the wash fastness of disperse dyes on wool. In the absence of oxidants, 10 disperse dyes from seven classes imparted colours with a range of depths ( K / S 2‐26) with wash fastness (grey scale ratings for colour change) grades of 3 to 4‐5. Hydrogen peroxide had only small effects on colours and gave only small enhancements to wash fastness, which were limited to anthraquinone, nitrodiphenylamine, disazo and coumarin dyes. The bleach activators Prestogen W and citric acid enhanced the bleaching effect of hydrogen peroxide but did not assist with raising wash fastness. Hydrogen peroxide in post‐dyeing scouring made the dyeings brighter but did not significantly enhance wash fastness. Ammonium persulphate, which was included for benchmarking with earlier studies, yellowed the wool and decomposed some dyes. This study extends the range of dye classes whose wash fastness on wool can be improved by ammonium persulphate to now include diazo, coumarin and methine, and confirms that oxidants/free radical initiators have potential for enabling the disperse dyeing of wool.