Diethylene glycol (chemical formula: C₄H₁₀O₂), often abbreviated as DEG, is a colorless, odorless, and hygroscopic (water-attracting) organic compound. It is a type of glycol (a diol), which means it contains two hydroxyl groups (-OH), making it similar in structure to other glycols like ethylene glycol and propylene glycol.
It is a byproduct of ethylene glycol production, and it has a wide range of industrial and commercial applications, though its use in consumer products is limited due to potential toxicity.
Properties:
- Molecular Formula: C₄H₁₀O₂
- IUPAC Name: 2-Hydroxyethylethanol
- Molar Mass: 106.12 g/mol
- Boiling Point: 245°C (473°F)
- Melting Point: -8°C (17.6°F)
- Density: 1.118 g/cm³ (at 20°C)
- Solubility: Soluble in water, alcohol, and most organic solvents
Key Uses of Diethylene Glycol (DEG):
Solvent in Chemical Manufacturing:
DEG is used as a solvent in the production of various chemicals, including:
- Paints, varnishes, and coatings.
- Inks for printing and dyeing.
- Lubricants and plastics.
Polymer Production:
DEG is involved in the production of polyester resins, particularly in the manufacture of polyester fibers.
- Polyurethanes: It acts as a soft segment in polyurethane production, used in foams, adhesives, and elastomers.
Antifreeze and De-icing Fluids:
Diethylene glycol is used in the formulation of antifreeze and coolants, though it is less commonly used than ethylene glycol due to its toxicity.
Humectants and Plasticizers:
DEG is used as a plasticizer to enhance flexibility in plastics and as a humectant in cosmetics, though its use is limited due to its potential toxicity.
Hydraulic Fluids and Heat Transfer Fluids:
DEG is used in hydraulic fluids and some heat transfer fluids, where its properties allow it to be effective in systems requiring high thermal stability.
De-icing:
Similar to other glycols, DEG is used for aircraft de-icing or runway de-icing, although it is less common than PG and EG.