Understanding the Effect on Hair Fibers of Coloring and Bleaching Formulations Using High Pressure Differential Scanning Calorimetry (HPDSC)

The 2007 study "Understanding the Effect on Hair Fibers of Coloring and Bleaching Formulations Using High Pressure Differential Scanning Calorimetry (HPDSC)" used HPDSC to measure changes in the denaturation temperature of hair's crystalline components after treatment with retail colorant and bleach products. The study found that a decrease in the HPDSC peak temperature after treatment is due to two effects: (1) the oxidative breakdown of the keratin protein matrix covalent bonds, which is a permanent change, and (2) the addition of formulation components such as salts, surfactants, or alkalisers that change the electrostatic environment in the matrix proteins, which is a reversible change. However, the study was unable to establish a significant correlation between increasing lightening, tensile strength, and HPDSC denaturation temperature for typical retail bleach or color treatments.