Reactivity of the Sulphur Linkage in Wool

Abstract

THE view that disulphide bond breakdown in the cuticle of wool fibres is responsible for their resistance to felting after treatment with chlorine, sodium hydroxide and sulphuryl chloride has been confirmed¹ by showing that wool treated with 0.1 N sodium hydroxide solution for 10–24 hr. at 22.2°C. is more resistant to these reagents than untreated wool. Treatment with sodium hydroxide was believed to convert a high proportion of the disulphide bonds into the more resistant lanthionine and —CH=N— cross-linkages ; but since there is now doubt² about the existence of the latter in alkali-treated wool, it seemed advisable to repeat the experiments with wool which had been treated with potassium cyanide. Cuthbertson and Phillips have shown² that most of the cystine in loose wool is converted into lanthionine by treatment with a 1 per cent solution of potassium cyanide for only 30 min. at 66° C. :