Hair Oxidation

Brenner, L., Squires, P. L., Garry M., and Tumosa, C. S. (1985). A measurement of human hair oxidation by Fourier transform infrared spectroscopy /. Forensic Sci. 30, 420-426. 

The silanization reaction has been used for some time to alter the wetting characteristics of glass, metal oxides, and metals [44]. While it is known that trichlorosilanes polymerize in solution, only very recent work has elucidated the mechanism for surface reaction. A novel FTIR approach allowed Tripp and Hair to prove that octadecyl trichlorosilane (OTS) does not react with dry silica. 

Permanent Hair Colorants. Permanent colorants produce hair coloration that lasts until the hair grows out. Color is formed inside the hair by hydrogen peroxide-induced coupling reactions of colorless dye precursors. A hiU range of shades can be obtained with this system and the permanent or oxidative hair colorants are considered to be the most important class of hair dyes. 

Also present but not essential in permanent hair colorants are nitro dyes which dye hair without oxidation. These dyes, nitro derivatives of aminophenols and benzenediamines, impart yellow, orange, or red tones. Although they have good tinctorial value, they are not as colorfast as the oxidative dyes. They also are used in semipermanent hair colorants. 

Melanin Drying. One development (ca 1993) in hair coloring involves the formation of pigments within the hair that are very similar to natural melanin. Thus either catalytic or air oxidation of 5,6-dihydroxyindole [3131-52-0] can be effectively used to permanently dye hair within a short time (38). The formed color can, if required, be further modulated with dilute H2O2 or can be even totally removed from hair by this oxidant. 

Neutralizing Lotion. The principal active ingredient of cold wave neutralizers is usually an oxidizing agent. The most popular is hydrogen peroxide [7722-84-1J, employed at a concentration of 1—2% it continues to find widespread use. Aqueous solutions of sodium bromate [7789-38-0] at a concentration of 10—20% occasionally are used and are technically preferred over the peroxide formulations because of excellent stabiUty and absence of hair bleaching. Neutralizing powders appear to be on the decline but formulations stiU in use consist of sodium perborate [7632-04-4] combined with hexametaphosphates to improve solubiUty in hard water. 

Hair straightening compositions based on mixtures of ammonium bisulfite [10192-30-0] and urea [57-13-6] have been introduced and have found some apphcation in the Caucasian hair market. The reformulation of the cystine cross-links in bisulfite-reduced hair is best accompHshed by a rinse, pH 8—10, rather than by the use of oxidizing agents (66). 

Surfactants and Dispersants. Castor od can be transformed from an od- to a water-soluble surfactant, depending on the moles of ethylene oxide added to its hydroxyl group. A 40 mole ethylene oxide adduct of castor od, known as PEG-40 castor od, is a surfactant that has cosolvent properties and is utilized as a fragrance solubilizer (118). Glycol hydroxystearate emulsifiers are formulated into shampoos to impart finer peadescence and give better stabdity than gylcol stearates (118) (see Hair preparation). 

Microemulsions, temporary emulsions, that is, two-layer haH dressHigs, and clear solutions of nonvolatile lubricants are on the market. HaH tonics, usually hydro-alcohoHc, achieve similar effects by including Hpid substances or synthetic em ollients, such as the mono butyl ethers of polypropylene oxides [9003-13-8] (10—50 mol). The primary benefits of these Hpid-based products are lubrication and improvements Hi haH gloss and hair-hoi ding (dressHig)... 

Hair bleaching removes the pigment melanin from the hair shaft by oxidative destmction. Alkaline hydrogen peroxide is the agent of choice. 

Table 17. Intermediates Used in Oxidation Hair Dyes ...

Propyl gallate is used to protect oils and fats in products from oxidation. It is used in foods, cosmetics, hair products, adhesives, and lubricants. 

Sometimes rather than adding color to a product, it is necessary to take color away. We bleach our clothes, our hair, and sometimes even our food. Most often chemicals react with colorful compounds to make them colorless through a process called oxidation. 

However, the most famous hair bleach is hydrogen peroxide. Unlike sunlight and lemon juice, peroxide is an oxidizing bleach, and its effects are less easily undone. 

When ammonium lauryl sulfate is reacted with ethylene oxide, the result is the larger molecule ammonium laureth sulfate. This molecule has the same detergent and surfactant qualities, but it is larger consequently it does not penetrate the skin and hair as easily. The term laureth is actually a contraction of lauryl ether. The full name is ammonium lauryl ether sulfate. 

Susan Solomon and James Anderson showed that CFCs produce chlorine atoms and chlorine oxide under the conditions of the ozone layer and identified the CFCs emanating from everyday objects, such as cans of hair spray, refrigerators, and air conditioners, as the primary culprits in the destruction of stratospheric ozone. The CFC molecules are not very polar, and so they do not dissolve in rain or the oceans. Instead, they rise to the stratosphere, where they are exposed to ultraviolet radiation from the Sun. They readily dissociate in the presence of this radiation and form chlorine atoms, which destroy ozone by various mechanisms, one of which is... 

Hydrogen peroxide is normally sold for industrial use as a 30% by mass aqueous solution. When used as a hair bleach (as a 6% solution), it acts by oxidizing the pigments in the hair. A 3 % H2Q2 aqueous solution is used as a mild antiseptic in the home. Contact with blood catalyzes its disproportionation into water and oxygen gas, which cleanses the wound ... 

Immediately after the face is covered with the solution, waterproof zinc oxide non-perme-able tape is applied to the skin, anchoring it to the hair line. Taping is made using short strips of 3.0 cm in the overlapping fashion. Over-... 

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