39—stress Changes at Constant Strain and Hydrogen Bonding in Keratin Fibres

When a keratin fibre is extended in water, held, and dried, a stress develops in the fibre. This stress is minimal for an extension of approximately 2%. The strain dependence of developed stress, and some properties of fibres at strains in the region of 2%, are discussed in terms of postulated hydrogenbond formations. Data are included on swelling, on deuterium for hydrogen exchange in strained fibres, on recovery of length, and on attempts to determine stress against strain curves under conditions in which fibre regain remained constant while the curves were determined.