The Fate of Thioglycollic Acid in Wool Durably Creased with Thioglycollate

The fate of thioglycollic acid in wool fabrics durably creased with ammonium thio glycollate was investigated. The effect of various treatments was followed by means of S³⁵-labelled thioglycollate, which was added to the ammonium thioglycollate solution used in imparting a crease. It is shown that steam ironing is not associated with loss of labelled thioglycollate. whereas washing with water results in rapid loss of radioactivity, followed by a much slower decrease. Almost complete loss of radioactivity can be brought about by treatment with sulfide, sulfite, or alkaline cyanide, whereas lithium bromide or urea has little effect. It is concluded that of the 4-9 mg. thioglycollate initi ally applied per gram of wool, 3-5 mg. are in a labile but nonvolatile state, whereas the remaining 1-4 mg. are probably in a mixed disulfide form. At the most this represents 4 or 8% of the half-cystine residues available in wool as the mixed disulfide. The find ings are discussed in the light of current theories of permanent setting.