Effects of Water Soluble Wool Keratin on Bleaching and Permanent Waving Treatments of Hair

Bleaching and permanent waving (B&P) treatments were carried out up to 3 times on Japanese woman virgin hair. B&P in the presence of water soluble wool keratin (carboxymethylalanyl disulfide keratin, CMADK) (BPW) was also carried out. CMADK prepared at pH 13.5 and 60°C for 3h was dissolved in the permanent waving agent and used to treat human hair. The surface of B&P treated hair was gradually damaged with increase of treatment times. BPW treated hair had less damage compared to B&P treated hair. The disulfide bonds changed to cysteic acid with treatment times. Elastic modulus and stress at yield point of treated hair were smaller than those of untreated hair. However, the decrease was smaller in BPW hair than that in B&P hair. The hair permed in the presence of CMADK had solid wave compared to B&P treated hair. All the results suggested the efficiency of CMADK to reduce hair damage caused by bleaching and permanent waving treatments.