A role of the anteiso branch of 18-MEA in 18-MEA/SPDA to form a persistent hydrophobicity to alkaline-color-treated weathered hair
The effect of the anteiso-branch moiety of 18-MEA (18-methyleicosanic acid) to create a persistent hydrophobicity of alkaline-color-treated weathered hair treated with 18-MEA/SPDA (stearoxypropyldimethylamine) was investigated by comparing a straight-chain fatty acid (n-heneicosanoic acid, n-HEA) and an iso-branch fatty acid (19-methyleicosanic acid, 19-MEA) with the anteiso-branch fatty acid (18-MEA), using dynamic contact angle measurements, quantification of 18-MEA by LC/MS, and temperature controlled atomic force microscopy (AFM). The dynamic contact angle measurements indicated that the anteiso-branch moiety of 18-MEA is critical for the creation of a persistent hydrophobicity to alkaline-color-treated weathered hair. The temperature-controlled AFM investigations revealed that the anteiso-branch moiety of 18-MEA in the 18-MEA/SPDA system produces a persistent hydrophobicity to alkaline-color-treated weathered hair by providing higher fluidity to the upper region of the 18-MEA/SPDA layer.
Document Type: Abstract
Affiliations: 1: Beauty Research Center, Kao Corporation, 2-1-3, Bunka, Sumida-ku, Tokyo 131-8501; 2: Analytical Science Research Laboratories, Kao Corporation, 1334 Minato, Wakayama-shi, Wakayama, 640-0112 and 3: Analytical Science Research Laboratories, Kao Corporation, 2606 Akabane, Ichikai, Haga, Tochigi 321-3497, Japan
Publication date: June 1, 2010