an unsaturated dibasic carboxylic acid, H2C=C(COOH)—CH2COOH; colorless crystals. Melting point, 167°-168°C.
Itaconic acid yields chloranhydride on heating with thionyl chloride; it yields esters upon interaction with alcohols. It combines with halogens and hydrogen halides in a double bond and readily polymerizes during storage (hydroquinone can be used as an inhibitor). Itaconic acid is used in the manufacture of synthetic detergents; its esters are used in the production of copolymers with methacrylates and styrene, and as polyvinylchloride plasticizers.