Mechanism of Action of Bis-Ethoxydiglycol Cyclohexane 1,4-Dicarboxylate in Alleviating Wavy Hair Undulation

Abstract

Bis-ethoxydiglycol cyclohexane 1,4-dicarboxylate (BECD), a water-and oil-soluble ester oil, contains hydrophilic (oxyethylene chain) and hydrophobic (cyclohexane ring) groups on the same molecule. The wavy hair undulation relaxed, and its restoration after 24 h was suppressed when wavy hair soaked in the BECD aqueous solution was hand-straightened and dried with a hair dryer. BECD was adsorbed on the non-keratin proteins, and straightening and drying wet wavy hair with a hair dryer caused BECD to easily promote the contraction and rearrangement of the elongated and deformed molecular chains and promote the homogenization of the aggregate structures of the non-keratin proteins, thereby relaxing undulation. Wavy hair not treated with BECD does not undergo uniform contraction or rearrangement of the molecular chains of the non-keratin proteins during the glassification process involving hair being straightened from wet conditions and finger-dried. This results in variations in the morphology of the aggregated structure of the non-keratin tissue, resulting in undulation. Contrastingly, the contraction and rearrangement of the constituent molecular chains of the non-keratin protein proceeded easily in the BECD-treated wavy hair, and the homogenization of the aggregated structure was promoted, which is thought to suppress undulation. The molecular mobility and moisture absorption characteristics of wavy hair were reduced after drying, and only slight contraction and rearrangement occurred over time. This may have inhibited the wavy hair from returning to its original state.