Polysorbate-20, also known as Tween-20, is a non-ionic surfactant with the chemical name polyoxyethylene (20) sorbitan monolaurate. It is synthesized by the condensation of sorbitan monolaurate with ethylene oxide under alkaline conditions^[2]. It appears as a yellow or amber clear oily liquid with an HLB value of 16.7, functioning as an oil-in-water (O/W) emulsifier. It is highly soluble in polar solvents such as water and ethanol but poorly soluble in mineral oils and light petroleum^[1][3].

This substance is widely used in cosmetics, pharmaceuticals, textiles, and other industries, primarily serving as an emulsifier, solubilizer, stabilizer, and antistatic agent. It is often used in combination with Span-20 to optimize performance. Its quality standards include saponification value (45–55 KOH mg/g), hydroxyl value (90–110 KOH mg/g), and acid value (≤2 KOH mg/g). Testing methods involve saponification titration, acetylated hydroxyl value determination, and Karl Fischer moisture analysis.