Description
Emulsifiers fall under the chemical class of surfactants or surface-active substances, more specifically water-soluble surface-active substances. Emulsifiers, which reduce the interface tension and counteract droplet enlargement, are divided into ionic products (mostly anionic; soaps) and non-ionic products (ethoxylates). Soluble oils require that water and oil are emulsified rapidly and form stable emulsions. Emulsifiers (e.g. alkali salts of FAs) are used in lubricants for cutting, grinding and drilling applications in machine shops. Self-emulsifying surfactants combine lubrication and emulsification in one product. Demulsifiers promote separation of water and oil in lubricants exposed to water of contamination, such as industrial oils in circulation systems (hydraulic, gear, turbine and compressor oils). Demulsifiers and emulsifiers use the same class of chemical substances (surfactants). Special polyethylene glycols are highly efficient demulsifiers.
