Chemical Reactions Involved in the Shrinkproofing of Wool by Oxidation-Sulfite Processes

The production of shrink resistance in wool by treatments which involve oxidation by peracetate on permonosulphate and subsequent treatment with sulphite is shown to be dependent on particular chemical reactions. These reactions have been followed by disulfide and thiol analyses on intact and hydrolyzed wool samples and also by measure ments of rate of uptake of 35SO3 2- from solution by wool. Oxidation 'of wool with dilute peracetic acid converts the disulfide groups into di sulfide monoxide and dioxide, thus facilitating fission by nucleophilic reagents such as sulfite or cyanide. The results support the theory of Neish and Speakman that shrink resistance in wool is produced by fission of disulfide bonds.