The Effects of Iodination and Related Modifications on the Supercontraction of Wool Fibers

Abstract

Iodination of wool fibers in ethanol or n-propanol accelerates the first stage and retards the second stage of supercontraction. Iodination in aqueous KI₃ has little effect on the rate of the first stage but retards the second stage of supercontraction. Evidence is presented that the rate of supercontraction is affected by at least two chemical processes which occur during iodination in ethanol : oxidation of sulfhydryl and disulfide groups, and the reaction of ethanol with the fiber in the presence of HI with consequent esterifica tion of carboxyl groups. Oxidative treatments, such as reaction with peracetic acid, aqueous KI₃, or ethanolic I₂ are considered to retard sulfhydryl-disulfide interchange reactions which determine the rate of the second stage of supercontraction.