Glykols

Glykols are a class of organic compounds comprising diols—molecules bearing two hydroxyl (-OH) groups. The term describes a family of glycols used as solvents, antifreeze agents, humectants, and polymer precursors. Common members include ethylene glycol (ethane-1,2-diol) and propylene glycol (propane-1,2-diol), as well as higher diols such as 1,4-butanediol and neopentyl glycol. Glykols are typically polar and highly miscible with water, with relatively high boiling points for their molecular weight and low volatility compared with many other alcohols.

Production and supply: Most industrial glycols are produced from epoxides via hydrolysis or hydration. Ethylene glycol is derived from ethylene oxide hydrolysis, while propylene glycol comes from propylene oxide hydrolysis. Other diols are produced by similar routes or through catalytic hydrogenation of suitable precursors. The choice of route depends on the target diol and required purity.

Applications: Glykols are used as antifreeze agents in automotive and industrial cooling systems; as solvents and intermediates in paints, inks, and polymer formulations; as humectants in cosmetics and foods; and as polymer precursors for polyesters, polyurethanes, and biodegradable materials. Some glycols are used in pharmaceutical formulations as excipients. Their properties, such as water miscibility and solvent strength, influence their selection for specific applications.

Safety and environment: Toxicity varies by compound. Ethylene glycol is highly toxic if ingested and can cause severe kidney injury; propylene glycol is generally less toxic but should be handled with care. Glycols can contaminate water and soils in spills; they are often biodegradable but may persist depending on conditions. Proper handling, ventilation, and disposal are advised.