adipihappo

Adipihappo, known in English as adipic acid and scientifically as hexanedioic acid, is a white, crystalline dicarboxylic acid with the chemical formula C6H10O4. It contains carboxyl groups at both ends of a six-carbon aliphatic chain and is a prominent industrial commodity chemical.

In its pure form, adipic acid is sparingly soluble in water at room temperature and becomes more soluble when warmed. It melts around 150–155 °C and forms various salts and esters that are used in chemical synthesis. The compound is relatively stable under ordinary conditions but can decompose at elevated temperatures.

Industrial production of adipic acid is dominated by the catalytic oxidation of KA oil, a mixture of cyclohexanone and cyclohexanol, using air and metal oxide catalysts. This process yields adipic acid, which is subsequently purified by crystallization. Alternative routes exist, including oxidation of related cyclohexane-derived intermediates. The scale of production makes adipic acid a key intermediate in the chemical industry.

The principal use of adipic acid is as a monomer in the production of nylon-6,6, via a condensation reaction with hexamethylenediamine. It also serves as a precursor for polyurethanes and various resins, plasticizers, and specialty polymers. In the food industry, adipic acid is used as an acidity regulator and is assigned regulatory status in many regions under the E numbers system (for example, as E355 in some jurisdictions).

Safety and handling considerations include standard precautions for handling acids: avoidance of inhalation of dust, and avoidance of skin or eye contact. Adipic acid is typically regarded as of low acute toxicity when handled properly, with environmental and regulatory guidelines governing its use and disposal.