The Effect of Various Cosmetic Pretreatments on Protecting Hair from Thermal Damage by Hot Flat Ironing

This study investigated the effects of various polymeric pretreatments on protecting hair from thermal damage caused by hot flat irons, which operate at temperatures over 200 °C. Techniques such as FTIR imaging spectroscopy, DSC, and SEM were used to analyze hair damage and protein degradation. The study found that thermal stress led to increased hair breakage, but pretreatments with polymers like VP/acrylates/lauryl methacrylate copolymer, polyquaternium-55, and a polyelectrolyte complex significantly reduced breakage. These pretreatments protected the native protein structure, improved moisture restoration, and enhanced cuticle integrity, providing thermal protection and reducing hair surface damage.