Chemical name: Thioglycolic Acid, 2-Mercapto Acetic Acid, 2-Mercapto Ethanoic Acid, Glycolic Acid, 2-thio
Common name: TGA, TGA 80%, TGA 99%
Arkema offers thioglycolic acid (TGA) with a minimum purity of 99%, as well as an aqueous 80% solution that offers longer shelf life.
Key Benefits of Thioglycolic Acid
At temperatures above 70°C – common temperatures in well bores, TGA is more efficient than classic ferric ion chelating agents (citric acid, acetic acid, EDTA, NTA). Moreover, TGA is more efficient than classic ferric reducing agents, such as erythorbic acid or ascorbic acid.
- TGA reduces Fe3+ (ferric) ions to chelated Fe2+ (ferrous) ions that remain in solution at pH < 7.5
- TGA is stable and efficient at low pH (TGA rapidly reduces high quantities of Fe3+)
- TGA can control very high concentrations of ferric iron - up to about 10%.
A wide range of Industrial applications
Due to its mercaptan functional group, thioglycolic acid and its salts provide essential properties in a wide range of applications.
The salts of thioglycolic acid and also some of its esters are used in the formulation of perms and for the preparation of depilatory creams. In these applications, the main salts are ammonium thioglycolate and potassium thioglycolate. In some areas, glycerol monothioglycolate is also used.
Oil & Gas
ATG is used in several areas of the oil and gas industry:
- As a reducing and chelating agent to limit Fe3+ precipitation during well drilling.
- In the catalytic cracking of hydrocarbons for oil refining, thioglycolic acid mercaptides act as a passivating agent to limit the contamination of metal catalysts (Ni, V, etc.)
- Thioglycolic acid (TGA) is also used as an additive in corrosion inhibiting formulations.
TGA is a very effective chain transfer agent for emulsion polymerizations in aqueous media, in particular for acrylic acid and acrylates. The total miscibility of TGA with water is a benefit in this application.
Thioglycolic acid is used for the preparation of pesticides such as thifensulfuron herbicide, or for polythiols or thio-esters.
In this industry, environmental requirements force manufacturers to develop processes that are more resource-efficient and less polluting. Baths based on sodium thioglycolate, used for the treatment of hides, are much less harmful to the environment than those based on sodium sulfhydrate. In addition, the use of sodium thioglycolate considerably reduces the amount of sulfide required for depilating.
Due to their ability to complex with metals, thioglycolic acid and thioglycolic acid salts are excellent additives in cleaning solutions, in particular for automotive applications including automotive wheel rim cleaners.
Mining and Metal recovery/treatment
TGA derivatives are also used as depressants in flotation processes for separating valuable metals from ores in mining operations. TGA derivatives are a safer alternative to the more traditional sodium sulfhydrate (NaSH), particularly in mining environments.
The bronsted acid characteristics of thioglycolic acid and its thiol functionality make it a chemical of choice for the preparation or regeneration of metal catalysts for hydrodesulfurization.