What Is Phthalic Anhydride?

Phthalic anhydride is the organic compound with the formula C₆H₄(CO)₂O. It is the anhydride of phthalic acid. Phthalic anhydride is a principal commercial form of phthalic acid. It was the first anhydride of a dicarboxylic acid to be used commercially.

What is phthalic anhydride used for?

The primary use of phthalic anhydride (PA) is as a chemical intermediate in the production of plasticizers from polyvinyl chloride (PVC). The primary use of phthalic anhydride (PA) is as a chemical intermediate in the production of plastics from vinyl chloride.

What is phthalic anhydride made from?

Phthalic anhydride is presently obtained by catalytic oxidation of ortho–xylene or naphthalene. When separating the phthalic anhydride from production by products such as o–xylene in water, or maleic anhydride, a series of “switch condensers” is required. Phthalic anhydride can also be prepared from phthalic acid.