Dioctyl Adipate (DOA)

Brief Overview

Dioctyl adipate (DOA) is a clear, colorless, and odorless liquid organic compound that belongs to the family of adipate esters. It is derived from the reaction of adipic acid with 2-ethylhexanol and is commonly used as a plasticizer in various industrial applications. DOA is known for its low volatility, good electrical properties, and excellent low-temperature flexibility, which makes it a popular choice for applications that require flexibility even at low temperatures. It is also widely used in the food packaging industry, as it is approved by the FDA for use as a food contact material. However, DOA is not without its drawbacks. It has a relatively low resistance to extraction by water, which can limit its use in certain applications. Additionally, it has a limited resistance to high-temperature environments, which can cause it to degrade over time. Despite these limitations, DOA remains a widely used and important industrial chemical.

Manufacturing Process

1. Esterification: Adipic acid and 2-ethylhexanol are mixed together in the presence of a catalyst such as sulfuric acid. The mixture is heated to around 220-240°C while being stirred continuously. The reaction produces a mixture of esters, including DOA, along with water as a byproduct.

2. Purification: The mixture is then allowed to cool, and the DOA is separated from the other esters using a distillation column. The DOA is collected as a clear, colorless liquid.

3. Refining: The DOA is further purified using various refining techniques, such as filtration or centrifugation, to remove any impurities that may be present.

1. Flexible plastics: DOA is used as a plasticizer in the production of flexible PVC (polyvinyl chloride) products, such as artificial leather, wallpaper, and electrical wire coatings. It improves the flexibility, durability, and resistance to low temperatures of these products.

2. Resins: DOA is used as a plasticizer in the production of various types of resins, such as alkyd resins, which are used in paints, varnishes, and coatings.

3. Synthetic rubber: DOA is used as a plasticizer in the production of synthetic rubber, such as nitrile rubber and styrene-butadiene rubber, to improve their flexibility and low-temperature properties.

4. Food packaging: DOA is approved by the FDA as a food contact material and is used as a plasticizer in the production of food packaging materials, such as films and containers.

5. Other applications: DOA is also used in other applications, such as in the production of adhesives, sealants, and lubricants.