Antioxidant

Description

A substance added in small quantities to an organic compound to inhibit oxidation. Antioxidants are typically added to hydrocarbons that are susceptible to oxidation, such as rubbers, plastics, foods, and oils. Antioxidants work in two different ways. The first, called a free-radical scavenger, reacts with peroxy radicals before they can attack the hydrocarbon. These antioxidants are usually hindered amines or substituted phenolic compounds. The second antioxidant type, called a peroxide decomposer, deactivates a hydroperoxide group after it is formed. Examples of this type of antioxidant are sulfides, thiodipropionates and organophosphites. Chelating agents are often added to scavenge metal impurities which could otherwise initiate decomposition.

See also Hindered phenol, Aromatic amine, and Hindered amine light stabilizer.

Synonyms and Related Terms

anti-oxidant; inhibitor; antioxidant (Ces., Dan., Ned.); Antioxidantien (Deut.); antioxidante (Esp., Port.); antioxidanter (Sven.)

Sources Checked for Data in Record

• G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 65

• Ralph Mayer, A Dictionary of Art Terms and Techniques, Harper and Row Publishers, New York, 1969 (also 1945 printing)

• Theodore J. Reinhart, 'Glossary of Terms', Engineered Plastics, ASM International, 1988

• Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993

• Matte Paint: Its history and technology, analysis, properties and conservation treatment, Eric Hansen, Sue Walston, Mitchell Bishop (ed.), J. Paul Getty Trust, Los Angeles, Vol. 30 of AATA, 1993

• Pam Hatchfield, Pollutants in the Museum Environment, Archetype Press, London, 2002

• Van Nostrand's Scientific Encyclopedia, Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976

• Wikipedia, the free encyclopedia, at http://www.wikipedia.com Comment: http://en.wikipedia.org/wiki/Antioxidant (Accessed Mar. 20, 2006) -for non-English terms

• Random House, Webster's Encyclopedic Unabridged Dictionary of the English Language, Grammercy Book, New York, 1997

• The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998

• Art and Architecture Thesaurus Online, http://www.getty.edu/research/tools/vocabulary/aat/, J. Paul Getty Trust, Los Angeles, 2000