Etoksülaatsioon

Etoksülaatsioon is an industrial chemical process in which ethylene oxide is added to a substrate molecule to create a linear polyethylene glycol chain. The reaction typically proceeds under acidic or basic conditions and can be carried out with a variety of starting materials, including alcohols, fats, and fatty acids. The product of etoksülaatsioon is a polyether compound that can vary in molecular weight depending on the number of ethylene oxide units incorporated.

Historically, the first successful large‑scale implementation of this reaction dates back to the 1940s, when it was pursued primarily for the synthesis of nonionic surfactants and emulsifiers. Over time, improvements in catalyst design and reactor engineering have increased both yield and safety. The use of Lewis acid or Brønsted acid catalysts, such as sulfuric acid or titanium-based systems, has become standard in many modern plants.

The basic mechanism involves ring opening of ethylene oxide, followed by nucleophilic attack on the substrate and successive addition of further ethylene oxide molecules. Reaction conditions are carefully controlled to minimize side reactions such as ether cleavage or cationic polymerization that could produce toxic by‑products. In many processes, the reaction mixture is cooled and the excess ethylene oxide is distilled off to improve product purity.

Etoksülaatsioon products find application in detergents, lubricants, cosmetics, and pharmaceutical excipients. Their amphiphilic nature makes them effective as surfactants, while their low toxicity and biodegradability are benefits for environmental compliance. The process also enables the tailoring of molecular weight and chain length, which directly influences the physical properties of the final product, such as viscosity and solubility.