maleïneanhydride

Maleïneanhydride, known in English as maleic anhydride, is an organic compound with the formula C4H2O3. It is the anhydride of maleic acid (cis-butenedioic acid). The substance appears as a colorless to white crystalline solid and melts at relatively low temperature; it hydrolyzes readily in water to maleic acid. It is a reactive dienophilic compound that can form adducts with various nucleophiles and can copolymerize with olefins and styrene derivatives.

Industrial production of maleic anhydride is accomplished by catalytic oxidation of hydrocarbon feedstocks, primarily benzene or butenes/butane, in the gas phase. The process uses catalysts based on vanadium pentoxide or related oxides and operated at high temperatures to promote selective partial oxidation to the anhydride. Global supply chains depend on these large-scale oxidation processes, with phenyl and alkene feedstocks varying by region and market conditions.

Applications of maleic anhydride are extensive in polymer chemistry and materials manufacturing. It is a key monomer for unsaturated polyester resins and alkyd resins, enabling crosslinking with styrene and other vinyl comonomers. It also serves as a versatile intermediate in the synthesis of agrochemicals, pharmaceuticals, plasticizers, and specialty chemicals, where its reactive anhydride group enables diverse transformations.

Safety and handling considerations include its irritant properties and corrosivity. It reacts with moisture to form maleic acid and can pose inhalation and skin contact hazards. Storage and handling require moisture control and appropriate protective measures to minimize exposure.