Impact of Acid Straightener's pH Value on Hair Fiber Properties
June 2019
in “
Journal of cosmetic dermatology
”
Studysummary In this study, tresses treated with pH 1.0 acid straightener showed better straightening but more damage to hair properties compared to those treated with pH 2.0. Our plain-language summary of this paper — not a Tressless recommendation.
The study analyzed the impact of acid straightener products with pH values of 1.0 and 2.0 on hair shaft properties. Tresses treated at pH 1.0 showed a 59.4% improvement in combing tests compared to 33.0% at pH 2.0, but also experienced a greater decrease in tensile strength (16.0% vs. 9.0%) and lower tryptophan content. Differential scanning calorimetry indicated impairment in straightened tresses, and environmental scanning electron microscope images suggested a film formation around the fiber. The study concluded that lower pH values caused more significant modifications to the hair shaft.