Stabilizer (chemistry)

In chemistry a stabilizer is a chemical which tends to inhibit the reaction between two or more other chemicals.^{[citation needed]} It can be thought of as the antonym to a catalyst. The term can also refer to a chemical that inhibits separation of suspensions, emulsions, and foams.^{[citation needed]} Stabilizers are usually added to polymers during production. The trend is towards fluid systems, pellets, and increased use of masterbatches. There are monofunctional, bifunctional, and polyfunctional stabilizers.^[1]

Some kinds of stabilizers are:

• antioxidants, preventing unwanted oxidation of materials
• sequestrants, forming chelate complexes and inactivating traces of metal ions that would otherwise act as catalysts
• emulsifiers and surfactants, for stabilization of emulsions
• ultraviolet stabilizers, protecting materials, especially plastics, from harmful effects of ultraviolet radiation
  • UV absorbers, chemicals absorbing ultraviolet radiation and preventing it from penetrating the materials; principally the same as sunscreens
  • quenchers, dissipating the radiation energy as heat instead of letting it break chemical bonds; often organic nickel salts, e.g. nickel phenolates
  • scavengers, eliminating the free radicals formed by ultraviolet radiation; often hindered amine light stabilizers (HALS)

See also

• Corrosion inhibitor
• Stabilizers for polymers

References