Ammonium thioglycolate, also known as perm salt, is a salt of mercaptoacetic acid and ammonia. Its chemical formula is hsch2co2nh4, which is used for perm.

Ammonium thioglycolate is a weak acid and weak base salt, which exists in solution as an equilibrium mixture of salt itself, mercaptoacetic acid and ammonia. Hsch2coo −+nh4+++hsch2cooh+NH3 mercaptoacetate can destroy the disulfide bond, cover hydrogen on one side, and form a new disulfide on the other side. RSH+R 'SSR'+R 'SSR'


For perm

The solution containing ammonium thioglycolate contains a large amount of free ammonia, making the hair swell and permeable. Thioglycolic acid contained in hair gel solution can reduce the disulfide cystine bond in cortex. In a sense, mercaptoacetic acid eliminates cross-linking. After washing hair, use a mild hydrogen peroxide solution to oxidize cysteine to cystine. These new chemical bonds provide the structural rigidity required for successful perm. The curing process is similar to vulcanization of rubber. Polysulfide bonds are usually used to crosslink polymer chains. However, it will not reorganize as many disulfide bonds as the previous permanent bonds. Therefore, your hair will be more fragile than before perm, and repeated perm in the same place will eventually damage your hair. Because polar molecules are less volatile than nonpolar molecules, glycolic acid substituents make mercaptan less volatile and reduce odor. Another advantage is that glycolic acid has a certain degree of water solubility. It is almost possible to perm with hsch3 and ammonia, but it will seriously affect your sense of smell.

 

In popular culture

In the 2001 film legal blonde, ellewoods, the heroine and law student, won her first lawsuit by proving that the witness who permed on the day of the murder could not have been in the shower at the time of the murder. Things to do. The first rule of perm maintenance is not to wet your hair for at least 24 hours after perm, because it may cause ammonium thioglycolate to lose its activity. "