Effects of Silicone Oil Viscosity on the Physical Structure and Damage Mechanisms of Hair During Permanent Wave Treatment

This study examined how different viscosities of silicone oil affect hair structure and damage during permanent wave treatments on untreated, permanent wavy, and dyed hair. Using dimethicone with viscosities of 6 cSt, 1,000 cSt, and 10,000 cSt, the researchers assessed wave efficiency, hair thickness, and tensile force. The highest wave efficiency was observed in untreated hair with low viscosity, permanent wavy hair with medium viscosity, and dyed hair with high viscosity. Hair thickness remained consistent across all groups, but tensile force, cuticle thickness, and sulfur content, which indicates hair damage, were highest with high viscosity treatments. The study concludes that silicone oil viscosity significantly impacts wave curling performance and hair damage, offering valuable insights for optimizing hair treatment formulations.