Abstract
Permanent waving (P), bleaching (B), and bleaching and permanent waving (B&P) treatments have been done up to 3 times on virgin Japanese human hair. The properties of treated hairs were investigated by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and amino acid analysis. The cuticle layers were hardly changed by 3 times of P and B treatments. However, the damage of cuticle was observed for 3 times treated B&P hair. FT-IR spectrum of the original hair showed characteristic features of keratin fiber, i.e., amide I (~1640cm-1), amide Il (~1530cm-1), and amide Ill (~1230cm-1). New weak absorptions corresponding to cysteic acid appeared at ~ 1040 cm-1 and ~ 1180cm-1 on IR spectra of P and B treated hair. For B&P treated hair, the peaks of cysteic acid increased remarkably with increase of treatment times. Amino acid composition for each treated hair hardly changed except for cystine. The amount of the cysteic acid in the various treated hairs increased in order of P L.T. S B L.T. B&P treatments. It was found that the damage of hair is encouraged synergistically by repetition of B & P treatment.
