Thioglycolic
acid, a simple sulfur group- chained carboxylic acid, is a clear liquid; melts
at -16. c, boils at 96 C; soluble in water. It is an useful chemical
intermediate in the chemical reactions such as addition, elimination and
cyclization. Sulfur group will react with bases, acids, ketones and organic
halogen compounds, whereas the carboxylic group will preferentially react In the
presence of alcohols or amines. The applications of thioglycolic acid and its
derivatives are wide in the fields of PVC stabilizers, down-hole acidizing,
corrosion inhibition in the oil field industry, manufacturing of
pharmaceuticals, agrochemicals and dyes, shrink-resistant treatment of wool, fabric
dying, leather processing.
Thioglycolates are used in cosmetic hair-care products especially permanent
waving products as they weaken the keratin structure by the opening of
the cystine disulfide linkages. In addition to hair-waving application, they
are used as depilating agents to remove
unwanted body hair. The break-down of disulfide bonds in the cortex by thioglycolates
either
rearranges (permanent
waving) or entirely destroys (depilating) hair structure. As an antioxidant application in cosmetics, thioglycolates
protect the product itself not the skin against oxidative reactions promoted by
ultraviolet radiation or oxygen.
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