Deposition of 18-MEA onto Damaged Hair to Form a Persistent Hydrophobicity

The study found that 18-MEA (18-methyleicosanoic acid) could be effectively re-deposited onto damaged hair to restore its hydrophobic and low-friction properties, which are often lost due to alkaline treatments like hair coloring. By combining 18-MEA with a specific long-chain tertiary amine (stearoxypropyl dimethylamine: SPDA), the researchers developed a technique to form a highly adsorptive film on the hair surface. This film, with its alkyl groups facing outward, uniformly covered the hair and created a liquid-like phase at the surface, enhancing friction resistance. Tests with conditioners containing 18-MEA and SPDA showed improved smoothness, reduced flyaway and frizzy hair, and better overall hair manageability.