Supercontraction and Elongation of Modified Keratin Fibers in LiBr Solution

Abstract

Reduced keratin fibers when heated in 8 M LiBr solution at 100° C first contract and then lengthen. Reduced and methylated Corriedale wool fibers contract but do not lengthen under the same conditions. Reduced fibers that have been abraded to remove cuticle lengthen less than unabraded fibers. Mechanical, x-ray, and birefringence evi dence show that fibers that have increased to about their natural length are severely degraded and not elastomeric. In general the amount of elongation increases with increasing severity of the reducing treatment. It is suggested that elongation results primarily from a swelling pressure within the fiber produced by dissolution of protein.