Diethylene Glycol

Basic Information

Properties: Colorless, odorless, transparent, hygroscopic viscous liquid with a pungent odor; non-corrosive.

Boiling point (°C, 101.3 kPa): 245

Melting point (°C): -10.5

Relative density (g/mL, 4°C): 1.118

Refractive index (15°C): 1.4490

Refractive Index at Room Temperature (n25): 1.446

Viscosity (mPa·s, 20°C): 35.7

Flash Point (°C): 143

Ignition Point (°C): 229

Heat of Vaporization (kJ/mol, b.p.): 52.297

Heat of Combustion (kJ/mol): 2380.2

Specific Heat Capacity (kJ/(kg·K), 20ºC): 2.31

Electrical Conductivity (S/m, 20°C): 5.86×10⁻⁷

Vapor Pressure (kPa, 20°C): <0.0013

Thermal Expansion Coefficient (K⁻¹ at 20°C): 0.000635

Solubility: Miscible with water, ethanol, ethylene glycol, acetone, chloroform, furfural, etc. Insoluble in diethyl ether, carbon tetrachloride, carbon disulfide, straight-chain aliphatic hydrocarbons, aromatic hydrocarbons, etc.

Application

1. Primarily used as a gas dehydrating agent and aromatic extraction solvent. Also serves as a solvent for nitrocellulose, resins, oils, printing inks, etc., as well as a softener and finishing agent for textiles, and for extracting coumarone and indene from coal tar. Additionally, diethylene glycol serves as a brake fluid additive, celluloid softener, antifreeze agent, and diluent in emulsion polymerization. It is also employed in the production of rubber and resin plasticizers; polyester resins; fiberglass; urethane foams; lubricant viscosity improvers; and other products. It is used in synthesizing unsaturated polyester resins, among other applications.
2. Used in synthesizing unsaturated polyester resins and plasticizers. Also employed as antifreeze agents, gas dehydrators, plasticizers, solvents, aromatic extractants, cigarette moisture absorbers, textile lubricants and finishing agents, anti-drying agents for pastes and various adhesives, and moisture-absorbing solubilizers for reduction dyes. It serves as a common solvent for oils, resins, and nitrocellulose. 
3.Diethylene glycol is a key raw material in polyurethane synthesis. Polyurethane, an elastic polymer material, finds extensive applications in furniture, automotive, construction, textiles, waterproof coatings, adhesives, and more. As the flexible segment component in polyurethane, diethylene glycol enhances material flexibility while also functioning as a crosslinking agent.
4. As a solvent and humectant, diethylene glycol dissolves dyes, paints, and inks, making it a vital raw material for printing, dyeing, and coatings industries. It also serves as an electrical fluid in brake fluids and capacitor electrolytes. In cosmetics and skincare products, diethylene glycol functions as a moisturizer and emollient, improving product hydration and user experience.
5. As an intermediate, diethylene glycol can synthesize other organic compounds like surfactants, plasticizers, and lubricants. It also serves in synthesizing fragrances and pharmaceuticals.
6. In pesticides, diethylene glycol produces herbicides such as glyphosate.
7. In pharmaceuticals, it manufactures various drugs including antibiotics and antineoplastic agents; it also functions as a local anesthetic.
8. In the fuel sector, diethylene glycol can be blended with other compounds to produce renewable energy sources like biodiesel.
9. In the food industry, diethylene glycol serves as a stabilizer and humectant, helping maintain food freshness and texture. It can also function as a disinfectant for food packaging materials