[Chemical Knowledge]：Properties, uses, upstream and downstream raw materials, storage methods, methacrylic acid action

Methacrylic acid properties

Methyl methacrylate (MMA) is a colorless transparent liquid with a pungent odor. It has the chemical formula C4H6O2, a molecular weight of 86.09g/mol, a density of about 0.94g/cm³, a melting point of 15°C, and a boiling point of 100.3°C. Methacrylic acid has high chemical reactivity, especially prone to polymerization to produce polymethacrylic acid (Polymethyl methacrylate, PMMA). The solubility in water is low, but it can be miscible with a variety of organic solvents, such as ethanol, acetone and benzene.

Methacrylic Acid Uses

Methacrylic acid is widely used in various industrial fields, and one of the most important uses is the production of polymethacrylate resins. This resin is commonly used in the manufacture of organic glass (acrylic), its high transparency, good mechanical strength, weather resistance, so it is widely used in construction, automobile, advertising display and other fields. Methacrylic acid is also used in the production of coatings, adhesives, textile finishing agents and paper coating agents. In the medical field, methacrylic acid is used to produce bone cement and dental materials.

Methacrylic acid upstream and downstream raw materials

Methacrylic acid production relies primarily on two main raw materials: acrylonitrile and methanol. Hydrocyanic acid (HCN) is generated by hydrogenation of acrylonitrile, and then esterified with methanol under acidic conditions to generate methacrylate, and finally methacrylic acid is generated by hydrolysis. The process also involves the disposal of some by-products, such as ammonium chloride and hydrogen. In the downstream application of methacrylic acid, polymerization is a key step. Different types of polymers are prepared by free radical polymerization, cationic polymerization and other methods to meet various industrial needs.

Methacrylic acid production process

At present, the main production processes of methacrylic acid include acrylonitrile method and ethylene method. Acrylonitrile method is a relatively mature process, the raw materials are easy to obtain and the reaction conditions are mild, and the by-product treatment is relatively simple. Ethylene law is the use of ethylene, methanol and air, through a multi-step oxidation reaction to produce methacrylic acid. The advantage of this method is that the raw material cost is low, but the reaction conditions are higher and the equipment investment is large. In recent years, with the development of green chemical technology, the improvement of catalyst and the optimization of reaction conditions, the application prospect of ethylene process is more broad.

Methacrylic Acid Storage Methods

Since methacrylic acid has high reactivity and is particularly prone to polymerization, it is necessary to take appropriate measures to prevent self-polymerization during storage. The polymerization reaction is generally inhibited by adding a polymerization inhibitor such as hydroquinone or a derivative thereof. Methacrylic acid should be stored in a cool, well-ventilated warehouse, away from fire and high temperature environment. Tanks and piping shall be of corrosion resistant material such as stainless steel or carbon steel lined with a corrosion resistant coating. During storage, the effectiveness of the polymerization inhibitor should be checked regularly, and necessary safety measures should be taken to prevent leakage and accidents.

Methacrylic Acid Market Prospects

With the continuous development of the global economy, the demand for methacrylic acid is increasing year by year. Especially in the construction, automobile, electronics and other industries, the market prospect of methacrylic acid is very broad. The application of acrylic products in architectural decoration and advertising display is becoming more and more common, and in the automotive industry, the demand for lightweight materials has also promoted the application of polymethacrylate. With the increasingly stringent environmental regulations, the application of methacrylic acid in water-based coatings and green adhesives is gradually expanding.

Environmental and Safety Considerations

Methacrylic acid is a volatile organic compound (VOC), which is harmful to the environment and human health. Therefore, it is necessary to strictly control its emissions during production and use. The factory should be equipped with effective waste gas treatment devices to reduce harmful gas emissions. During operation, personal protection should be strengthened to avoid skin contact and inhalation of high-concentration vapors. In case of leakage accident, people should be evacuated immediately and emergency measures should be taken to deal with the leakage to prevent environmental pollution.

Summary

Methacrylic acid as an important chemical raw material, its wide application and good market prospects make it an important part of the chemical industry. Due to its high reactivity and potential environmental hazards, strict control measures are required during production, storage and use. In the future, with the continuous progress of technology and the development of green chemical industry, the production and application of methacrylic acid will be more efficient, safe and environmentally friendly.