industrial chemistry The chemical industry comprises the company, companies and other organizations that develop and produce industrial, specialty and other chemicals. Central to the modern world economy, the chemical industry converts raw materials (Petroleum, oil, ...

, a stabilizer or stabiliser is a chemical that is used to prevent

degradation Degradation may refer to: Science * Degradation (geology), lowering of a fluvial surface by erosion * Degradation (telecommunications), of an electronic signal * Biodegradation of organic substances by living organisms * Environmental degradation ...

. Above all, heat and light stabilizers are added to

plastic Plastics are a wide range of synthetic polymers, synthetic or Semisynthesis, semisynthetic materials composed primarily of Polymer, polymers. Their defining characteristic, Plasticity (physics), plasticity, allows them to be Injection moulding ...

and

rubber Rubber, also called India rubber, latex, Amazonian rubber, ''caucho'', or ''caoutchouc'', as initially produced, consists of polymers of the organic compound isoprene, with minor impurities of other organic compounds. Types of polyisoprene ...

materials because they ensure safe processing and protect products against aging and weathering. In particular

polyvinyl chloride Polyvinyl chloride (alternatively: poly(vinyl chloride), colloquial: vinyl or polyvinyl; abbreviated: PVC) is the world's third-most widely produced synthetic polymer of plastic (after polyethylene and polypropylene). About 40 million tons of ...

would not be possible without stabilizers (PVC is one of the most important plastics and used for pipes, window frames and many other products). In economic terms the most important product groups on the market for stabilizers are compounds based on

calcium Calcium is a chemical element; it has symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to it ...

(calcium-

zinc Zinc is a chemical element; it has symbol Zn and atomic number 30. It is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodic tabl ...

and organo-calcium),

lead Lead () is a chemical element; it has Chemical symbol, symbol Pb (from Latin ) and atomic number 82. It is a Heavy metal (elements), heavy metal that is density, denser than most common materials. Lead is Mohs scale, soft and Ductility, malleabl ...

, and

tin Tin is a chemical element; it has symbol Sn () and atomic number 50. A silvery-colored metal, tin is soft enough to be cut with little force, and a bar of tin can be bent by hand with little effort. When bent, a bar of tin makes a sound, the ...

stabilizers as well as liquid and light stabilizers ( HALS,

benzophenone Benzophenone is a naturally occurring organic compound with the formula (C6H5)2CO, generally abbreviated Ph2CO. Benzophenone has been found in some fungi, fruits and plants, including grapes. It is a white solid with a low melting point and ros ...

benzotriazole Benzotriazole (BTA) is a heterocyclic compound with the chemical formula . It can be viewed as the fusion of a benzene and triazole rings. It is a white solid, although impure samples can appear tan. It is used as a corrosion inhibitor for copper. ...

Cadmium Cadmium is a chemical element; it has chemical symbol, symbol Cd and atomic number 48. This soft, silvery-white metal is chemically similar to the two other stable metals in group 12 element, group 12, zinc and mercury (element), mercury. Like z ...

-based stabilizers largely vanished in the last years due to health and environmental concerns. In 2023, almost half of all polymer stabilizers sold worldwide were based on calcium.

Polymers (plastics and elastomers)

Stabilizing additives for plastics are produced in different forms. The trend is towards fluid systems, pellets, and increased use of masterbatches. There are monofunctional, bifunctional, and polyfunctional stabilizers. Some kinds of stabilizers are: *

antioxidant Antioxidants are Chemical compound, compounds that inhibit Redox, oxidation, a chemical reaction that can produce Radical (chemistry), free radicals. Autoxidation leads to degradation of organic compounds, including living matter. Antioxidants ...

s these prevent

autoxidation Autoxidation (sometimes auto-oxidation) refers to oxidations brought about by reactions with oxygen at normal temperatures, without the intervention of flame or electric spark. The term is usually used to describe the gradual degradation of organi ...

of materials and come in 3 primary forms. ** Oxygen scavengers (primarily

phosphite ester file:Phosphite.svg, The general structure of a phosphite ester showing the lone pairs on the P In organic chemistry, a phosphite ester or organophosphite usually refers to an organophosphorous compound with the formula P(OR)3. They can be conside ...

s such as tris(2,4-di-tert-butylphenyl)phosphite) are commonly used during the initial processing of the plastic. ** Persistent

radical Radical (from Latin: ', root) may refer to: Politics and ideology Politics *Classical radicalism, the Radical Movement that began in late 18th century Britain and spread to continental Europe and Latin America in the 19th century *Radical politics ...

scavengers prevent or slow the photo-oxidation of polymers. Traditionally these are alkylated phenols such as

butylated hydroxytoluene Butylated hydroxytoluene (BHT), also known as dibutylhydroxytoluene, is a lipophilic organic compound, chemically a derivative of phenol, that is useful for its antioxidant properties. BHT is widely used to prevent free radical-mediated oxidation ...

but now also include

hindered amine light stabilizers Hindered amine light stabilizers (HALS) are chemical compounds containing an amine functional group that are used as stabilizers in plastics and polymers. These compounds are typically derivatives of tetramethylpiperidine and are primarily used ...

(HALS) **

Antiozonant An antiozonant, also known as anti-ozonant, is an organic compound that prevents or retards damage caused by ozone. The most important antiozonants are those which prevent degradation of elastomers like rubber. A number of research projects stud ...

s prevents or retards the degradation of polymers caused by

ozone Ozone () (or trioxygen) is an Inorganic compound, inorganic molecule with the chemical formula . It is a pale blue gas with a distinctively pungent smell. It is an allotrope of oxygen that is much less stable than the diatomic allotrope , break ...

(

ozone cracking Cracks can be formed in many different elastomers by ozone attack, and the characteristic form of attack of vulnerable rubbers is known as ozone cracking. The problem was formerly very common, especially in tires, but is now rarely seen in those ...

) *

sequestrant A sequestrant is a food additive which improves the quality and stability of foods. A sequestrant forms chelate complexes with polyvalent metal ions, especially copper, iron and nickel. This can prevent the oxidation of the fats in the food. Sequ ...

s, forming chelate complexes and inactivating traces of metal ions that would otherwise act as catalysts * ultraviolet stabilizers are used to protect polymers from effects of

ultraviolet Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of ...

radiation and come to 2 main types. ** UV absorbers which essentially act the same way as

sunscreen Sunscreen, also known as sunblock, sun lotion or sun cream, is a photoprotection, photoprotective topical product for the Human skin, skin that helps protect against sunburn and prevent skin cancer. Sunscreens come as lotions, sprays, gels, fo ...

s ** Quenchers, which dissipate the radiation energy as heat instead of letting it break chemical bonds; often organic

nickel Nickel is a chemical element; it has symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive, but large pieces are slo ...

salts, e.g. nickel

phenolate Phenolates (also called phenoxides) are anions, salt (chemistry), salts, and esters of phenols, containing the phenolate ion. They may be formed by reaction of phenols with strong base. Properties Alkali metal phenolates, such as sodium phenoxi ...

Paints

emulsifier An emulsion is a mixture of two or more liquids that are normally immiscible (unmixable or unblendable) owing to liquid-liquid phase separation. Emulsions are part of a more general class of two-phase systems of matter called colloids. Althou ...

s and

surfactant Surfactants are chemical compounds that decrease the surface tension or interfacial tension between two liquids, a liquid and a gas, or a liquid and a solid. The word ''surfactant'' is a Blend word, blend of "surface-active agent", coined in ...

s, for stabilization of

emulsion An emulsion is a mixture of two or more liquids that are normally Miscibility, immiscible (unmixable or unblendable) owing to liquid-liquid phase separation. Emulsions are part of a more general class of two-phase systems of matter called colloi ...

Food

In foods, stabilizers prevent spoilage. Classes of food stabilizers include emulsifiers,

thickener A thickening agent or thickener is a substance which can increase the viscosity of a liquid without substantially changing its other properties. Edible thickeners are commonly used to thicken sauces, soups, and puddings without altering their ...

s and gelling agents, foam stabilizers,

humectant A humectant is a hygroscopic (water-absorbing) substance used to keep things moist. They are used in many products, including food, cosmetics, medicines and pesticides. When used as a food additive, a humectant has the effect of keeping moistu ...

anticaking agent An anticaking agent is an additive placed in powdered or granulated materials, such as table salt or confectioneries, to prevent the formation of lumps ( caking) and for easing packaging, transport, flowability, and consumption. Caking mechanism ...

s, and coating agents.Erich Lück, Gert-Wolfhard von Rymon Lipinski "Foods, 3. Food Additives" in ''Ullmann's Encyclopedia of Industrial Chemistry'', 2002, Wiley-VCH, Weinheim. File:BigPhosphite31570-04-4.png,

Tris(2,4-di-tert-butylphenyl)phosphite Tris(2,4-di-tert-butylphenyl)phosphite is an organophosphorus compound with the formula C4H9)2C6H3Osub>3P. This white solid is a widely used stabilizer in polymers where it functions as a secondary antioxidant. It also reduces discoloration (y ...

is a widely used stabilizer in polymers. File:HALSgeneric.png, Partial structure of typical

, widely used to protect automotive paints from degradation by UV-light. File:Salpn.png, Salpn is a typical

metal deactivator Metal deactivators, or metal deactivating agents (MDA) are fuel additives and oil additives used to stabilize fluids by deactivating (usually by sequestering) metal ions, mostly introduced by the action of naturally occurring acids in the fuel ...

used as a fuel additive to suppress oxidation processes that lead to gums and solids. Metal deactivators like salpn form stable complexes with the metals, suppressing their catalytic activity.

References

Chemical kinetics Chemical compounds Material protection {{chem-compound-stub

Polymers (plastics and elastomers)

Paints

Food

See also

References