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.
Tanamachi
Hiroto
H
Beauty Research Center, Kao Corporation, Sumida-ku, Tokyo, Japan.
Inoue
Shigeto
S
Tokunaga
Shinichi
S
Tsujimura
Hisashi
H
Tanji
Noriyuki
N
Oguri
Masashi
M
Habe
Taichi
T
D002853:Chromatography, Liquid; D004537:Eicosanoic Acids; D006197:Hair / Q000737:chemistry*; D006202:Hair Dyes; D006801:Humans; D013058:Mass Spectrometry; D018625:Microscopy, Atomic Force
D004537:Eicosanoic Acids; D006202:Hair Dyes; C111345:18-methyleicosanoic acid