TLDR Permanent waving damages hair by disrupting its keratin structure.
The study examined the structural damage to keratin protein in human hair caused by permanent waving treatment using various spectroscopic methods. It was found that the treatment led to a partial disruption of the α-helical structure in the hair's microfibrils, primarily during the initial reduction process. This disruption resulted in the α-helix changing to a random-coil structure rather than a β-sheet. The incomplete re-oxidation of disulphide bonds was previously considered the main cause of damage, but this study highlighted the significant role of structural changes in the microfibrils. The findings were supported by techniques such as 13C CP/MAS n.m.r., WAXD, FTi.r., and Raman spectroscopy.
7 citations
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February 1998 in “Polymer journal” Keratin structure in hair is stable at pH 5-6 but disrupts between pH 6-7.
5 citations
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February 1998 in “Polymer” Human hair keratin has a 40% α-helix structure that changes to a random coil in 8 M urea.
85 citations
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January 1990 23 citations
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January 1981 Hair is mostly made of three protein types: helical, high-sulfur, and high-tyrosine.
November 2024 in “Biophysical Chemistry” Hair structure changes immediately during perm treatment, with initial damage partially restored later.
37 citations
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October 2015 in “PeerJ” Perming significantly changes hair's molecular structure, while shampoo and conditioner do not.
13 citations
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March 2019 in “Journal of cosmetic dermatology” Heat damages hair, with Asian hair losing more protein than Caucasian hair.
53 citations
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July 2016 in “Cosmetics” Future hair cosmetics will be safer and more effective.
25 citations
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May 2019 in “Heliyon” Hair treatments cause significant structural changes, especially with excessive heat, regardless of ethnicity.
