diglycol

Diglycol, commonly referring to diethylene glycol (DEG), is a diol consisting of two ethylene glycol units connected by an ether linkage: HO-CH2-CH2-O-CH2-CH2-OH. The term is sometimes used more broadly to denote related diglycol compounds, including diethylene glycol ethers such as diethylene glycol monomethyl ether and diethylene glycol monobutyl ether.

Chemical identity and properties: Diethylene glycol has the molecular formula C4H10O3 and a molecular weight of 106.12 g/mol. It is a colorless, hygroscopic liquid at room temperature, miscible with water and many organic solvents. It has a relatively high boiling point, about 244°C, and a low vapor pressure. DEG is typically produced as a stable, viscous liquid that can absorb moisture from the air.

Production and uses: DEG is produced industrially by the reaction of ethylene oxide with ethylene glycol under catalytic conditions. It serves as a versatile solvent for coatings, inks, adhesives, and polymer resins, and is also used as a plasticizer and humectant. In addition, it acts as an intermediate in the manufacture of other glycol ethers and resins. Different diglycol ethers, such as diethylene glycol monobutyl ether, are used as solvents in various industrial applications.

Safety and environmental considerations: Diethylene glycol is toxic if ingested and may cause kidney and liver damage; exposure can irritate skin, eyes, and the respiratory tract. It should be handled with appropriate personal protective equipment and proper engineering controls, and stored away from incompatible materials. Regulatory status varies by country, and DEG is typically not permitted for use in foods or cosmetics.