X-Ray Studies of the Structure of Hair, Wool, and Related Fibers. II. - The Molecular Structure and Elastic Properties of Hair Keratin
TLDR Stretched hair has a similar structure to natural silk, showing hair's elasticity involves reversible changes within its molecules.
The study examines the molecular structure and elastic properties of hair keratin through several hundred X-ray photographs of mammalian hairs and related fibers. It concludes that the X-ray fiber photograph of stretched hair (β-keratin) is similar to that of natural silk, indicating that stretched hair (α-keratin) consists of the same chains in a folded state. This suggests that the elastic mechanism of hair involves a reversible intra-molecular transformation.
