Phthalic Anhydride is an organic compound and the anhydride of phthalic acid (P384480). Phthalic Anhydride is an important industrial chemical commonly used in large-scale production of plasticizers f
or plastics. Recent research have also evaluated Phthalic Anhydride as potential antibacterial agent.
white crystalline solid with choking odour
A colorless to white lustrous solid in the form of needles with a mild distinctive odor. Moderately toxic by inhalation or ingestion and a skin irritant. Melting point 64°F Flash point 305°F. Forms a corrosive solution when mixed with water. Used in the manufacture of materials such as artificial resins.
manufacture of phthaleins, phthalates, benzoic acid, synthetic indigo, artificial resins (glyptal).
Phthalic anhydride is used in the manufacture of unsaturated
polyesters and as a curing agent for epoxy resins.
When used as a pigment, it can be responsible for sensitization
in ceramic workers. Phthalic anhydride per se is
not responsible for the sensitization to the resin used in
nail varnishes phthalic anhydride/trimellitic anhydride/
Combustible material: may burn but does not ignite readily. Substance will react with water (some violently) releasing flammable, toxic or corrosive gases and runoff. When heated, vapors may form explosive mixtures with air: indoors, outdoors and sewers explosion hazards. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapors may travel to source of ignition and flash back. Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated or if contaminated with water.
ChEBI: The cyclic dicarboxylic anhydride that is the anhydride of phthalic acid.
Distil the anhydride under reduced pressure. Purify it from the acid by extracting with hot CHCl3, filtering and evaporating. The residue is crystallised from CHCl3, CCl4 or *benzene, or sublimed. Fractionally crystallise it from its melt. Dry it under vacuum at 100o. [Saltiel J Am Chem Soc 108 2674 1986, Beilstein 17/11 V 253.]
Air & Water Reactions
Reacts, usually slowly with water to form phthalic acid and heat [Merck 11th ed. 1989]. The phthalic acid is somewhat soluble in water.
Phthalic anhydride reacts exothermically with water. The reactions are sometimes slow, but can become violent when local heating accelerates their rate. Acids accelerate the reaction with water. Incompatible with acids, strong oxidizing agents, alcohols, amines, and bases. Undergoes exothmeric nitration with fuming nitric acid-sulfuric acid and may give mixtures of the potentially explosive phthaloyl nitrates or nitrites or their nitro derivatives [Chem. & Ind. 20:790. 1972]. Phthalic anhydride reacts violently with CuO at elevated temperatures [Park, Chang-Man, Richard J. Sheehan. hthalic Acids and Other Benzenepolycarboxylic Acids Kirk-Othmer Encyclopedia of Chemical Technology. John Wiley & Sons, Inc. 2005]. Mixtures of Phthalic anhydride and anhydrous CO2 explode violently if heated [eaflet No. 5, Inst. of Chem., London, 1940].
Solid irritates skin and eyes, causing coughing and sneezing. Liquid causes severe thermal burns.