ADIPIC ACID

   TU UKRAINE 24.1-33270581-026:2008

Adipic acid HOOC(C2)4COOH is a white crystalline substance exhibiting all carboxylic acids characteristics. Can form salts most of which are readily soluble. Specified adipic acid is easily esterified into mono and diesters. It is used in production of hexamethylenediammoniumadipinate, hexamethylenediammoniumsebacinate, polyurethanes, has also found its application as plasticizer in production of plastics, as conservative in food industry; it is used in printing industry for high-grade paper manufacturing, Pharmaceuticals industry, as well as in production of diesters and dyes.

Uses

   By far the majority of the 2.5 billion kg of adipic acid produced annually is used as monomer for the production of nylon by a polycondensation reaction with hexamethylene diamine forming 6,6-nylon. Other major applications also involve polymers: it is a monomer for production of Polyurethane and its esters are plasticizers, especially in PVC.

In medicine

   Adipic acid has been incorporated into controlled-release formulation matrix tablets to obtain pH-independent release for both weakly basic and weakly acidic drugs. It has also been incorporated into the polymeric coating of hydrophilic monolithic systems to modulate the intragel pH, resulting in zero-order release of a hydrophilic drug. The disintegration at intestinal pH of the enteric polymer shellac has been reported to improve when adipic acid was used as a pore-forming agent without affecting release in the acidic media. Other controlled-release formulations have included adipic acid with the intention of obtaining a late-burst release profile.

In foods

   Small but significant amounts of adipic acid are used as a food ingredient as a flavorant and gelling aid. It is used in some calcium carbonate antacids to make them tart.

Safety

Adipic acid, like most carboxylic acids, is a mild skin irritant. It is mildly toxic, with an LD50 of 3600 mg/kg for oral ingestion by rats.