Reconnection Of Cysteine In Reduced Hair With Alkylene Dimaleates Via Thiol-Michael Click Chemistry

The study investigates a novel method to reconnect reduced disulfide bonds in hair using thiol-Michael click chemistry with 1,4-n-butylene dimaleate. Virgin black Chinese hair was reduced with 8% thioglycolic acid and treated with the Michael reagent. Raman and FT-IR spectroscopy confirmed chemical changes, while tensile testing and DSC assessed mechanical and thermal properties. Results showed that 1,4-n-butylene dimaleate significantly improved hair's mechanical strength by restoring α-helix structures and forming new C-S bonds, compensating for broken disulfide bonds. Similar Michael reagents also enhanced the mechanical properties of reduced hair, suggesting this method effectively restores hair keratin's secondary conformation and strength.