Adipic acid
Adipic acid is a six-carbon dicarboxylic acid, HOOC(CH₂)₄COOH, used chiefly to make nylon 6,6 and also in food and pharmaceutical products.
Nylon 6,6: A polyamide made by reacting hexamethylenediamine with adipic acid, widely used in fibers and engineering plastics. Adipic acid supplies the six-carbon diacid units in this major polymer.
Dicarboxylic acid: An organic compound containing two carboxyl groups. Adipic acid’s two terminal carboxyl groups define its characteristic reaction pattern.
Cyclohexane: A six-carbon saturated ring hydrocarbon used as a major industrial feedstock. Oxidation of cyclohexane produces intermediates that are further oxidized to adipic acid.
Nylon: A family of synthetic polyamides used in fibers, films, and molded parts. Nylon 6,6 makes adipic acid part of a much broader class of durable materials.
Hexamethylenediamine: A six-carbon diamine used with adipic acid to produce nylon 6,6. It is adipic acid’s reaction partner in nylon 6,6 manufacture.
Polycondensation: A polymer-forming reaction in which molecules join while releasing small molecules such as water. Adipic acid forms nylon 6,6 through repeated condensation with a diamine.
KA oil: A mixture of cyclohexanone and cyclohexanol formed by oxidation of cyclohexane. This industrial intermediate mixture is a common precursor to adipic acid.
Greenhouse gas emissions: The release of gases that absorb infrared radiation and contribute to planetary warming. Adipic acid manufacture has historically emitted nitrous oxide, linking its supply chain to climate impacts.
Food additive E355: The European food-additive designation for adipic acid, used chiefly as an acidity regulator. This designation covers adipic acid’s use to control acidity in foods.
Esterification: A reaction in which an acid and an alcohol form an ester, often releasing water. Its carboxyl groups can form adipate esters with alcohols.