Adipic acid is an important chemical raw material, scientists

Adipic acid is an important chemical raw material, and as a key chemical raw material, its molecular formula is C ₆ H ₁₀ O ₄ from a chemical structure perspective. It has a typical dicarboxylic acid structure, which gives it unique reactivity in the field of organic synthesis, such as the ability to undergo esterification reactions with alcohols. According to relevant literature, under the action of specific catalysts, the esterification rate with methanol can reach over 95%.
Scientists have found that adipic acid plays a crucial role in the polyester industry while studying it. Taking the production of polyester polyols as an example, the hydroxyl value range of polyester polyols formed by the reaction of adipic acid is usually between 50-200mg KOH/g. Products with different hydroxyl values are suitable for different polyurethane application scenarios. Adipic acid is an indispensable raw material in the synthesis of nylon-66. Scientists polymerize adipic acid with hexamethylenediamine through a condensation reaction, controlling the reaction temperature at 250 280 ℃ and pressure at 1.5-2.0MPa, to obtain high-quality nylon-66 products with a relative molecular weight of up to 1.5 × 10 ⁴ -3.0 × 10 ⁴. From the perspective of market demand, the global annual demand for adipic acid continues to grow due to its wide range of applications. According to statistics, the annual growth rate of global demand for adipic acid has remained stable at around 3% -5% in recent years, especially in emerging economies where demand growth is more pronounced. Scientists are committed to developing a greener and more environmentally friendly production process for adipic acid. The traditional method of preparing adipic acid by nitric acid oxidation using a mixture of cyclohexanone and cyclohexanol as raw materials has pollution problems. The new biocatalytic synthesis process uses specific enzymes as catalysts, with mild reaction conditions and a reaction temperature generally between 30-40 ℃, which can effectively reduce pollutant emissions.
The physical properties of adipic acid also affect its application. It is a white crystal with a melting point of 152 ℃ and a boiling point of 337.5 ℃. Its solubility in water varies significantly with temperature, with a solubility of about 2.3g/100g water at 25 ℃. This characteristic has important applications in its separation and purification process. In the lubricant industry, adipic acid ester derivatives are widely used as base oils for high-performance lubricants. Scientists have found that the flash point of certain adipic acid ester lubricants can reach over 200 ℃, and the pour point can be as low as -40 ℃, which can meet the lubrication needs in extreme environments. The purity requirements for adipic acid vary greatly in different application scenarios. In the field of high-end electronic chemicals, the purity of adipic acid is extremely high, and the impurity content needs to be controlled below the ppm level to ensure that the performance of electronic components is not affected. Scientists studying the reaction kinetics of adipic acid have found that in specific reaction systems, the reaction rate constants of adipic acid with certain amine compounds are exponentially related to temperature. According to the Arrhenius equation, the reaction rate at different temperatures can be accurately calculated to optimize the reaction conditions.
Adipic acid is also used in the field of food additives, but its use has strict regulations. In the food industry, adipic acid is used as an acidity regulator, and its maximum usage is clearly limited in different food categories, such as 0.1g/kg in jam and jelly.