Maleic anhydride

Main Applications

Maleic anhydride is a "bridge-type" chemical raw material, with downstream products covering multiple fields such as polymer materials, solvents, and pharmaceuticals:

Unsaturated Polyester Resin (UPR):

Largest application field (accounting for 40%-50% of maleic anhydride consumption): It reacts with polyols such as ethylene glycol and propylene glycol to generate unsaturated polyester, which is then copolymerized with styrene to form cross-linked fiberglass reinforced plastic (FRP). It is used in construction (pipes, storage tanks), automotive (parts), shipbuilding, etc., featuring light weight, high strength, and corrosion resistance.

Fine Chemical Intermediates:

Synthesis of Tetrahydrofuran (THF): Maleic anhydride is hydrogenated to first obtain succinic anhydride, which is then dehydrated and hydrogenated to generate THF (an important solvent used in the synthesis of PTMEG, i.e., spandex raw material).

Synthesis of γ-Butyrolactone: Maleic anhydride is directly hydrogenated to generate GBL (solvent, pharmaceutical intermediate, used in the synthesis of pyrrolidone).

Production of Fumaric Acid: A hydrolysis isomerization product of maleic anhydride, used as a food additive (acidulant, preservative) and feed additive (antioxidant).

Water Treatment and Material Additives:

Polymaleic anhydride (PMA) and its copolymers are efficient scale inhibitors and dispersants, used in industrial circulating water and boiler water treatment (to prevent calcium carbonate deposition).

As a modifier, it improves the adhesion and weather resistance of resins (e.g., in coatings, adhesives).

Pesticides and Pharmaceuticals:

Synthesis of herbicides (e.g., paraquat precursors) and fungicides (e.g., captan).

Preparation of intermediates for anti-ulcer and anti-inflammatory drugs (e.g., enalapril maleate).