Secondary Structure Estimation and Properties Analysis of Stretched Asian and Caucasian Hair

The study investigated the secondary structure and properties of stretched Asian and Caucasian hair using Fourier transform infrared spectroscopy, tensile curves, and density measurements. The results showed that stretching caused a transformation from α-helix to β-pleated structures and breakage of disulfide bonds. Caucasian hair, having a finer diameter and less medulla, was more prone to structural destruction than Asian hair. The density measurements confirmed that Caucasian hair's structure was more damaged. Additionally, the cuticles of Caucasian hair tended to collapse and flake off more easily during stretching, while Asian hair cuticles were more resistant to peeling. The study concluded that Caucasian hair was more easily destroyed by stretching compared to Asian hair.