Bunte-salt thiol exchange for repeatable low-damage styling

Overview

Jiangnan University has developed a novel, low-damage hair perming technology based on the Bunte salt–thiol exchange reaction. This research addresses the core industry challenge of hair damage caused by conventional oxidative perming, which relies on oxidizing agents that degrade disulfide bonds and weaken hair structure over time. By utilizing a bifunctional Bunte salt, specifically sodium hexamethylene-1,6-bisthiosulfate (SHB), this method enables efficient and repeatable hair styling while preserving the structural integrity of hair fibers.

Technical specifications

• Core Mechanism: Employs a Bunte salt–thiol exchange reaction to reconstruct disulfide bonds, avoiding the use of damaging oxidizing agents like hydrogen peroxide.
• Performance: Maintains high perming efficiency (920% after six cycles) compared to the significant decline observed in conventional oxidative methods.
• Hair Health: Increases disulfide bond content by 15.5% in treated hair, whereas conventional methods lead to a 10.7% depletion.
• Structural Integrity: Preserves cuticle morphology, surface hydrophobicity, and mechanical properties, with only marginal reductions in strength compared to virgin hair.
• Repeatability: Designed for multiple, consecutive perming treatments without the cumulative damage associated with traditional protocols.

Technology readiness level

4. This technology is currently in the laboratory validation and research stage. It has been successfully synthesized, characterized, and evaluated through systematic comparative studies against conventional oxidative methods using Chinese virgin hair. The research has been published in peer-reviewed scientific literature, demonstrating its potential for future application in hair care products.