Is Polysorbate 80 natural?

Sorbitol from corn starch dehydrated to sorbitan, esterified with vegetable oleic acid, then ethoxylated with 20 mol petrochemical ethylene oxide.

Polysorbate 80, also known as Tween 80, is a nonionic surfactant synthesized through a multi-step process. The first stage involves the conversion of sorbitol, a sugar alcohol, into sorbitan. This is achieved by heating sorbitol under vacuum to remove water molecules, forming cyclic ethers. Sorbitol itself is typically produced by the catalytic hydrogenation of glucose, which is readily available from renewable sources like corn starch.

The second key component is oleic acid, a monounsaturated fatty acid. Oleic acid is primarily obtained from the hydrolysis of triglycerides found in vegetable oils (e.g., palm oil, soybean oil, olive oil) or animal fats. The fatty acids are then separated, and oleic acid is purified.

The core reaction for producing polysorbates is the ethoxylation of sorbitan esters. In the case of Polysorbate 80, sorbitan is esterified with oleic acid to form sorbitan monooleate. This ester is then reacted with ethylene oxide (EO) in the presence of a basic catalyst, such as potassium hydroxide (KOH) or sodium hydroxide (NaOH). The reaction involves the ring-opening polymerization of ethylene oxide, adding multiple ethoxy units (-CH2CH2O-) to the hydroxyl groups of the sorbitan monooleate. Typically, an average of 20 ethylene oxide units are added per molecule, hence the '80' in the name (which is a code related to the average number of EO units).

The reaction is carried out under controlled temperature and pressure conditions, usually between 150-200°C and under pressure to maintain EO in the liquid phase. After the reaction, the catalyst is neutralized, and the product is purified to remove unreacted materials, byproducts (like polyethylene glycols), and residual catalyst. The degree of ethoxylation can be controlled to achieve specific surfactant properties.

Polysorbate 80 is a common ingredient found in many cosmetic and personal care products, acting as a versatile emulsifier and solubilizer. Think of it as a helper molecule that allows oil and water-based ingredients, which normally wouldn't mix, to blend together smoothly. This is crucial for creating stable lotions, creams, and even some makeup products.

It's made from two main parts: sorbitol, which comes from plant sugars like those found in corn, and oleic acid, a fatty acid derived from vegetable oils. These are combined, and then a process involving ethylene oxide is used to attach chains of 'ethoxy' units. While the sorbitol and oleic acid parts are renewable, the ethylene oxide is typically made from petroleum. Because of this mix, it's considered to have a balance between renewable and petroleum-derived origins.

CosIng definition: Sorbitan, mono-9-octadecenoate, poly(oxy-1,2-ethanediyl) derivs., (Z)-