STUDIES IN CHROME MORDANTING .3. OXIDATION OF WOOL BY CHROMIUM(6)

The effect of boiling wool in a chromium(VI) solution on the groups present in wool has been investigated. At low pH the disulphide bonds were oxidized directly, whereasat high pH the hydrolysis products of the disulphide bonds, such as hydrogen sulphide, rather than the disulphide bonds themselves were oxidized. In addition, tyrosine was oxidized throughout the pH range investigated (pH 2–9) and lysine was oxidized at high pH (pH 7–9), though not at low pH. The maximum chromium(III) uptake by the wool, for a given concentration of chromium(VI) in the bath, occurred at pH 4. © 1969, CSIRO. All rights reserved.