phthalic anhydride
Quick Summary
Phthalic anhydride is a colorless, crystalline organic compound that is primarily produced and sold in its anhydride form. It is a cyclic acid anhydride with the chemical formula C8H4O3.12
Annual production of phthalic anhydride surpassed 1,000,000 metric tons in the late 20th century. Its main uses include:1
* Polyesters: It is a key ingredient in polyesters, such as alkyd resins used in paints and enamels.1
* Plasticizers: Simple esters derived from phthalic anhydride are used to make polyvinyl chloride and other polymers more flexible.1
* Other applications: Smaller amounts are used in the production of dye intermediates like anthraquinone, laxatives and indicators like phenolphthalein, and pigments like phthalocyanine.1
Ask Britannica AI about this topic
Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.
carboxylic acidAromatic acidsPhthalic anhydride is used to make polymeric resins called alkyd resins, which are used as coatings, especially for appliances and automobiles. The para isomer, terephthalic acid, is also used to make polymers—namely, polyesters (see below Derivatives of carboxylic acids: Carboxylic esters).
Read MorePhthalic anhydride is used to make polymeric resins called alkyd resins, which are used as coatings, especially for appliances and automobiles. The para isomer, terephthalic acid, is also used to make polymers—namely, polyesters (see below Derivatives of carboxylic acids: Carboxylic esters).
Read More- carboxylic acidPolycarboxylic acids
heating, phthalic acid readily yields phthalic anhydride (with a five-membered ring), but isophthalic and terephthalic acids do not undergo this reaction.
Read Moreheating, phthalic acid readily yields phthalic anhydride (with a five-membered ring), but isophthalic and terephthalic acids do not undergo this reaction.
Read More
