[Chemical Knowledge]：Isophthalic acid properties, uses, upstream and downstream raw materials, storage methods, isophthalic acid is dangerous goods?

Properties of isophthalic acid

Isophthalic acid (Isophthalic acid, referred to as IPA) is an important organic chemical raw materials, chemical formula is C8H6O4. It is one of the three dicarboxylic acid isomers of benzene, the other two being terephthalic acid (Terephthalic acid) and phthalic acid (Phthalic acid). In the molecular structure of isophthalic acid, two carboxyl groups are located in the meta position (1,3-position) of the benzene ring, which gives it unique chemical and physical properties. Pure isophthalic acid is a white crystalline powder with a melting point of 345-348°C. It is almost insoluble in cold water, but has good solubility in hot water, ethanol and other organic solvents.

Uses of isophthalic acid

the application of isophthalic acid in industry mainly focuses on the following aspects:

1. polyester resin: Isophthalic acid is an important raw material for the production of high-performance polyester resins (such as unsaturated polyester resins and saturated polyester resins). Compared with terephthalic acid, isophthalic acid gives polyester better flexibility and heat resistance, so it is widely used in the production of glass fiber reinforced plastics, automobile parts, coatings and packaging materials.
2. Coatings and Inks: Isophthalic acid is used to manufacture high temperature resistant and corrosion resistant coatings and inks. Its presence improves the durability and service life of these materials, especially in applications in harsh environments, such as anti-corrosion coatings for ships, buildings and industrial equipment.
3. engineering plastics isophthalic acid is also used in the production of engineering plastics such as polyesteramides (PA) and liquid crystal polymers (LCP), which are widely used in the electronics, electrical and automotive fields due to their excellent mechanical properties and thermal stability.
4. drug intermediates in the pharmaceutical industry, isophthalic acid is a synthetic intermediate for certain drugs involved in the manufacture of antibiotics, anticancer drugs and other chemotherapeutic agents.

Upstream feedstock of isophthalic acid

the production of isophthalic acid usually uses m-xylene (m-Xylene) as the main raw material and is produced by oxidation reaction. The specific process is as follows:

1. raw material preparation: m-Xylene is an aromatic hydrocarbon extracted from petroleum and obtained through separation and refining.
2. catalytic oxidation: Under the action of a catalyst (such as cobalt-manganese-bromine system), m-xylene undergoes catalytic oxidation in air or oxygen to generate isophthalic acid.
3. Purification: The oxidation product is crystallized and filtered to remove impurities and obtain high-purity isophthalic acid.

Downstream products of isophthalic acid

the downstream products of isophthalic acid are mainly concentrated in the fields of polyester resins, coatings, engineering plastics and pharmaceutical intermediates. Specifically include:

1. unsaturated polyester resin: This resin is widely used in the manufacture of composite materials, such as glass fiber reinforced plastics, in industries such as construction, automobiles, ships and wind power equipment.
2. powder coating isophthalic acid is widely used in the production of powder coatings as a raw material for coating resins. These coatings are used for surface treatment of home appliances, furniture and automobiles due to their excellent durability and environmental protection characteristics.
3. liquid crystal polymer: This high-performance plastic has important applications in electronic and electrical fields, such as circuit boards, connectors and microelectronic components.
4. pharmaceutical intermediates: Through chemical synthesis process, isophthalic acid can be converted into a variety of drug intermediates, which can be used in drug development and production.

Storage method of isophthalic acid

since isophthalic acid has a certain chemical activity, its storage requires special attention. The main storage methods are as follows:

1. storage environment: Isophthalic acid should be stored in a dry, cool and well-ventilated warehouse, avoid direct sunlight and humid environment, to prevent the product from moisture absorption and degradation.
2. Packaging: usually lined with plastic bags woven bags or barrels to ensure that in the transport and storage process moisture, pollution prevention.
3. Keep away from fire source: Although isophthalic acid itself is not flammable, it may decompose to generate combustible gas at high temperature, so it should be away from fire source and high temperature environment, and the storage temperature is best controlled below 25°C.
4. Safety measures: Operators should wear protective gloves and masks when handling isophthalic acid to avoid dust inhalation and skin contact. The warehouse shall be equipped with appropriate fire fighting facilities to deal with possible emergencies.

Market Prospect and Development Trend

with the development of industry and technology, the market demand for isophthalic acid continues to grow. Especially in the field of high-performance materials and environmentally friendly materials, its application prospects are broad. In the future, the following development trends deserve attention:

1. green chemical process by improving the catalyst and process conditions, the green and efficient production process of isophthalic acid is realized, and the energy consumption and pollutant emission are reduced.
2. New material development new polyesters, coatings and engineering plastics developed based on isophthalic acid will play a role in more high-end applications, such as aerospace, electronic information and new energy.
3. circular economy: Promote the recycling of isophthalic acid and its derivatives, reduce resource consumption and environmental burden through chemical recycling and reuse technology, and promote sustainable development.

Conclusion

as an important organic chemical raw material, isophthalic acid occupies an important position in modern industry due to its unique properties and wide application prospects. From the upstream m-xylene raw material to the downstream polyester resin, coatings, engineering plastics and pharmaceutical intermediates, isophthalic acid plays a key role in the entire industrial chain. In the future, through technological innovation and the development of green technology, the application field of isophthalic acid will be further expanded, bringing more opportunities and challenges to related industries.