Adipic Acid, Hexanedioic Acid​​​​​​​, 124-04-9

Adipic Acid, Hexanedioic Acid, 124-04-9

 Adipic Acid

Molecular Formula: C₆H₁₀O₄
Molecular Weight: 146.14 g/mol
Chemical Name: Hexanedioic Acid
CAS Number: 124-04-9

General Information and Description

Adipic Acid is the most important dicarboxylic acid in terms of global production capacity. It is a rare chemical in nature. It has a tart taste and is typically found exogenously in both urine and blood. It appears as a white crystalline solid and is insoluble in water.

Other Names (Synonyms)

• Adipate

• Hexanedioic Acid

• Adipinic Acid

• 1,4-Butanedicarboxylic Acid

• 1,6-Hexanedioic Acid

• Hexane-1,6-dicarboxylate

• Adipicacid

• Adipinate

• Hexane diacid

• 124-04-9

• Salt Forms: Calcium Salt, Diammonium Salt

Production Method

The production of Adipic Acid involves two important reaction stages, with the first stage being an intermediate production step.

It is produced by the oxidation of cyclohexane, cyclohexanol, or cyclohexanone with air or nitric acid.

Almost all of the world's production is derived from cyclohexane.

Physical and Chemical Properties

• Physical Appearance: White crystalline solid with odorless crystals.

• Taste: Tart taste.

• Boiling Point: 337.5 °C at 760 mm Hg pressure.

• Melting Point: Between 151.5 °C and 154 °C.

• Flash Point: 196 °C.

• Solubility:

  • Insoluble in water.

  • Freely soluble in ethanol.

  • Insoluble in acetic acid and ligroin.

  • Not readily soluble in petroleum benzene.

• Density: 1.36 g/cm³.

• Stability: Stable under recommended storage conditions. Generally considered a stable chemical.

Use as a Food Additive

In the food industry, Adipic Acid functions as:

• An acidity regulator in jellies and jams

• A neutralizing agent

• A buffering agent

• An additive in dietetic products

Adipic Acid E Number: E 355

Currently, commercially produced Adipic Acid is derived from petroleum-based products (fossil sources). However, with rising oil prices and the demand for greener products, research into bio-based production has accelerated.

Bio-based Production Research:
Fermentation-based production methods show promise for manufacturing this chemical. Suitable feedstocks for fermentation include:

• Sugar-based raw materials

• Aromatic raw materials

• Fatty acid sources

Adipic Acid produced through fermentation is expected to become more widespread as a food additive.

Importance in Cable Manufacturing

Copper and aluminum wires deteriorate over time due to hydrocarbons and environmental factors, leading to cable aging.

To prevent cable aging, a series of processes are applied during manufacturing. Adipic acid-containing substances are used to reduce the aging effects caused by hydrocarbons. Polyester resins derived from dicarboxylic acids are used to coat copper wires with aging-resistant materials.

Adipic Acid is the most suitable dicarboxylic acid for preparing polyester resins for this purpose (along with oxalic acid).

Applications and Uses

Adipic Acid has a wide range of industrial applications:

1. Polymer Industry:

• Nylon Production: Used extensively as a monomer in the production of nylon 6,6.

• Polyester Production: Used in esterification reactions with succinic acid and 1,4-Butanediol to produce polyester resins via dehydration.

• Polyurethane Production: Used in the manufacture of certain polyurethanes.

2. Food Industry:

• As a gelling aid and texturizer in gelatins

• For providing acidity in food products

• As a buffering and leavening agent

• In the production of effervescent tablets (chlorine tablets)

3. Industrial Applications:

• Corrosion Inhibitor: Used as a corrosion inhibitor and scale prevention agent.

• Paint Stripping: Combined with ammonium nitrate in solutions (with monochloroacetic acid as a solvent) for effective removal of paints from ferrous and non-ferrous metals. This cleaning composition can also remove limescale and rust.

• Lubricants: Used in the manufacture of lubricant components.

• Adhesives and Sealants: Used in the production of adhesives and sealants.

• Water Treatment: Used in the manufacture of water treatment products.

4. Environmental Applications:

• Flue Gas Desulfurization: Used in compounds to capture sulfur from flue gases emitted by thermal power plant chimneys.

5. Pharmaceutical Applications:

• Used as a tarting agent in some calcium carbonate antacids.