Is PEG-100 Stearate natural?

Palm-derived stearic acid esterified with polyethylene glycol made from petrochemical ethylene oxide.

PEG-100 Stearate is an ester formed by the reaction of polyethylene glycol (PEG) with stearic acid. The '100' in the name is the average number of ethylene oxide units in the chain, a polyethylene glycol of about 4,400 g/mol. The synthesis involves an esterification reaction between the hydroxyl end-groups of PEG and the carboxyl group of stearic acid.

This reaction is typically carried out under elevated temperatures, often in the range of 150-200°C, and may require a catalyst to facilitate the esterification. Common catalysts include acidic catalysts like sulfuric acid or p-toluenesulfonic acid, or basic catalysts such as sodium hydroxide or potassium hydroxide. The reaction is usually performed under vacuum or with a stream of inert gas to remove the water byproduct, driving the equilibrium towards ester formation.

Following the esterification, the crude PEG-100 Stearate undergoes purification steps to remove unreacted starting materials, catalyst residues, and any byproducts. Purification methods can include neutralization of the catalyst, washing, filtration, and sometimes distillation or crystallization, depending on the desired purity and physical form of the final product. The final product is typically a waxy solid or flake.

PEG-100 Stearate is a synthetic ingredient commonly used in cosmetics to help mix oil and water-based ingredients, making it an effective emulsifier. Think of it like a bridge that allows oil and water to blend smoothly in products like lotions, creams, and conditioners, preventing them from separating.

It's made by combining two components: polyethylene glycol (PEG) and stearic acid. Polyethylene glycol is a water-soluble polymer made from petroleum-derived ethylene oxide, while stearic acid is a fatty acid from vegetable oils or animal fats. The glycol chain is by far the heavier part, so only about 6% of it is natural origin. The process involves chemically linking these two ingredients together, often at high temperatures, and then purifying the result to ensure it's safe and effective for use in your beauty products.

CosIng definition: Poly(oxy-1,2-ethanediyl), .alpha.-(1-oxooctadecyl)-.omega.-hydroxy- (100 mol EO average molar ratio)