70 citations
,
June 1998 in “Polymer” Permanent waving damages hair by disrupting its keratin structure.
5 citations
,
February 1998 in “Polymer” Human hair keratin has a 40% α-helix structure that changes to a random coil in 8 M urea.
45 citations
,
December 2006 in “Biopolymers” Permanent waving weakens hair by altering its protein structure.
7 citations
,
February 1998 in “Polymer journal” Keratin structure in hair is stable at pH 5-6 but disrupts between pH 6-7.
25 citations
,
May 2019 in “Heliyon” Hair treatments cause significant structural changes, especially with excessive heat, regardless of ethnicity.