Chemical Treatments Designed to Modify the Affinity of Wool for Dyes

Abstract

The dyeing properties of wool have been modified by treating it with a series of reactive hydrophobic, anionic and cationic compounds. The extent of fixation of these reactive compounds to the wool was determined as dry basis weight gains which reached 70–13% wt/wt for many of the compounds examined.The dyeing properties of the modified wools were examined with a series of anionic, cationic and reactive dyes. The hydrophobic mechanism of dyeing appears to predominate over the ionic mechanism, except for the highly ionised dyes examined. The monosulphonated dye C. I. Acid Red 88 was more strongly absorbed by hydrophobic wool (benzoylated or ANEX–treated wool) and had an improved wash fastness rating on the treated wool. C. I. Reactive Red 116 is effectively resisted by the reactive hydrophobic and anionic treatments since these compounds eliminate the nucleophilic sites normally available for reaction with reactive dyes.