[Chemical Knowledge]：Properties, uses, upstream and downstream raw materials, storage methods, uses of maleic anhydride

Maleic Anhydride Properties

Maleic anhydride (chemical formula: C4H2O3), also known as maleic anhydride, is a colorless or white solid with a pungent odor. Its molecular structure is a five-membered ring containing two carbonyl groups, chemical properties are lively, easy to react with water to generate maleic acid. Maleic anhydride has strong hygroscopicity and is easily soluble in organic solvents such as water, ethanol and ether. It has a melting point of 52-56°C and a boiling point of 202°C, and sublimates at high temperatures. The chemical activity of maleic anhydride is mainly manifested in its anhydride group, which makes it an important intermediate in many chemical reactions.

Maleic Anhydride Uses

Maleic anhydride is widely used in the chemical industry and is an important raw material for the production of a variety of chemical products. Its main uses include:

1. Resins and Plastics: Maleic anhydride is an important raw material for the manufacture of unsaturated polyester resins (UPR), which are widely used in the production of FRP, coatings and molding compounds. Maleic anhydride is also used in the production of alkyd resins and epoxy resins.

2. Coatings and Inks: Maleic anhydride-derived resins are widely used in coatings and inks due to their excellent adhesion and corrosion resistance.

3. Pharmaceuticals and pesticides: maleic anhydride is an important raw material for the synthesis of a variety of pharmaceutical and pesticide intermediates, such as maleic anhydride amide and maleic anhydride imine compounds.

4. Additives and Lubricants: Maleic anhydride is used to produce lubricant additives and modifiers for petroleum products to improve product performance and stability.

Maleic anhydride upstream and downstream raw materials

Upstream raw materials

Maleic anhydride production relies primarily on two feedstocks: benzene and n-butane.

1. Benzene method: benzene is oxidized by air to generate maleic anhydride. This is a traditional production method and the process is mature. However, due to the high price of benzene, it is gradually replaced.

2. n-butane method: n-butane is prepared by oxidation of maleic anhydride, which has the advantages of low cost and high yield, and has become the mainstream production process.

Downstream Products

Maleic anhydride has a wide range of downstream products, including unsaturated polyester resins, alkyd resins, plasticizers, coatings, pharmaceutical intermediates, etc. Through these downstream products, maleic anhydride is widely used in construction, automotive, electronics, medicine and agriculture.

Maleic Anhydride Storage Methods

Due to the strong hygroscopicity and pungent odor of maleic anhydride, its storage requires special attention to the following points:

1. Moisture-proof storage: maleic anhydride should be stored in a dry, well-ventilated warehouse to prevent moisture and heat. The packaging should be sealed to avoid prolonged contact with air.

2. Temperature control: The temperature of the storage environment should be controlled at low temperature to avoid sublimation and decomposition of maleic anhydride caused by high temperature. Storage at 0-30°C is generally recommended.

3. Fire and explosion -proof: maleic anhydride is flammable, the storage area should be far away from fire and heat sources, and the necessary fire fighting equipment should be equipped. A good ventilation system shall be provided in the warehouse to prevent the risk of fire and explosion due to the accumulation of volatiles.

4. Safety protection: during operation and storage, appropriate protective equipment, such as gloves, masks and goggles, should be worn to avoid irritation and damage to the skin and respiratory tract caused by maleic anhydride.

Conclusion

As an important chemical raw material, maleic anhydride is widely used in many fields due to its properties. Through the two main production processes of benzene and n-butane, maleic anhydride is produced in large quantities and used in the manufacture of resins, coatings, pharmaceuticals and pesticides. Due to its strong hygroscopicity and pungent odor, the storage of maleic anhydride requires strict environmental controls and safety measures. With the continuous progress of chemical technology, the production and application of maleic anhydride will continue to expand, and its market demand will continue to grow. In the context of environmental protection and sustainable development, optimizing the production process of maleic anhydride, improving resource utilization and reducing environmental pollution will become the key direction of future research and application.