English name: Polyoxyethylene Sorbitan Fatty Acid Esters
Other names: tween, Polysorbates, Polysorbatum and so on
Emulsifiers; nonionic surfactants, solubilizers, wetting agents, dispersing / suspending agents.
There is smell, warm and slightly bitter. Generally pale yellow to amber viscous liquid, but different due to differences in molecular weight.
PH: about 6-8 [5% (W / V) solution]
Flash point: 149 ℃
Stability: stable with electrolyte, weak acid and weak alkali; In case of strong acid and alkali gradually saponification. Its acid is easy to be oxidized. Hygroscopic, dry when necessary. Storage for too long will produce peroxide.
In a sealed container, dark, cool and dry place to store.
As the Span is formed with the sorbitol and different high-grade fatty acid ester, so Tween is actually the same type of product, in the general fine chemical shop or chemical reagents company 20,40,60,80 variety, according to different need to use.
Tween 20, Tween 40, Tween 60, Tween 80;
Tween-60 is a stearate; Tween-80 is an oleate; Tween-20 is a laurate.
As the polysorbate molecules have more hydrophilic groups of a polyoxyethylene, so hydrophilic, as a non-ionic surfactant.
Often used as oil-in-water (O / W) emulsifier, so that other substances evenly dispersed in the solution, mainly for pesticides, food, cosmetics. And other emulsifiers such as sodium lauryl sulfate or spoon in combination, can increase the stability of the emulsion. Tween can be used to emulsify the oil after dissolved in water, fully play a role. Relatively speaking, Tween 20 is more moderate, Tween 80 more emulsifying.