Definition of phthalic anhydride in English:

phthalic anhydride


mass nounChemistry
  • A crystalline compound made by oxidizing naphthalene, used as an intermediate in the manufacture of plastics, resins, and dyes.

    • ‘In one method, naphthalene is oxidized with vanadium pentoxide to give phthalic anhydride.’
    • ‘Succinic anhydride has almost the same rate constant as acetic, while maleic anhydride reacts 10 times as quickly and phthalic anhydride four times.’
    • ‘Alkyd resins are produced by the curing reaction of a material like phthalic anhydride with glycerol in the presence of a fatty acid.’
    • ‘Officials from China's Ministry of Foreign Trade and Economic Cooperation announced the measure targeting imports of phthalic anhydride to see whether they are sold at unfairly low prices and damaging local industries.’
    • ‘This fraction is most typically drawn from the lighter fractions such as ethylene which is used for making polyethylene plastic while the preformed aromatic rings in the heavier fractions find use in such products as phthalic anhydride.’


Mid 19th century: phthalic, shortening of naphthalic (see naphthalene).