Peg/Ppg-17/18 Dimethicone is an inorganic chemical compound, a Dimethicone by-product.

The name describes the structure of the molecule:

• "Peg/Ppg" refer to polyethylene glycol (PEG) and polypropylene glycol (PPG), respectively. They are synthetic polymers used in cosmetics for various purposes.
• "17/18" indicate the average length of the polymers, i.e., the average number of ethylene oxide or propylene oxide units in the polymer.
• "Dimethicone" is a type of silicone used in many cosmetic products for its emollient and film-forming properties  and the description of this component is explained later.

Description of raw materials used in production.

• Dimethicone. A silicon-based polymer used as the base ingredient.
• Ethylene oxide. Used to produce PEG (polyethylene glycol) groups on the dimethicone.
• Propylene oxide. Used to produce PPG (polypropylene glycol) groups on the dimethicone.
• Acid. Often used to catalyze the reaction.
• Catalysts. Often employed to expedite the reaction between ethylene oxide or propylene oxide and dimethicone.

Detailed summary of the production process.

• Dimethicone preparation. The dimethicone is purified and readied for reaction.
• Addition of ethylene oxide. Ethylene oxide is added to the dimethicone in the presence of a catalyst to create PEG groups.
• Addition of propylene oxide. Propylene oxide is then added to create PPG groups.
• Neutralization. Any residual acid or catalyst is neutralized.
• Purification. The product is purified to remove impurities or residual chemicals.

What it is used for and where

Cosmetics

Surfactant - Emulsifying agent. Emulsions are thermodynamically unstable and are used to soothe or soften the skin and emulsify, so they need a specific, stabilising ingredient. This ingredient forms a film, lowers the surface tension and makes two immiscible liquids miscible. A very important factor affecting the stability of the emulsion is the amount of the emulsifying agent. Emulsifiers have the property of reducing the oil/water or water/oil interfacial tension, improving the stability of the emulsion and also directly influencing the stability, sensory properties and surface tension of sunscreens by modulating the filmometric performance.

Commercial Applications

Cosmetic Products. Peg/Ppg-17/18 Dimethicone is often used as an emollient, skin and hair conditioning agent, and as a surfactant in various cosmetic products.

Hair Products. It can be found in shampoos, conditioners, and hair sprays where it helps to smooth hair and reduce frizz.

Creams and Lotions. Used as a thickening agent in skincare products.

Safety

Dimeticone ((polydimethylsiloxane) is a chemical compound, a high molecular weight polymer derived from silicone, a chemically inert mixture of linear methylated siloxane polymers. The term 'dimeth' denotes two methyl groups bonded to the silicone molecule that provide the formation of dimethicone. It possesses a pronounced viscoelasticity characteristic and is hydrophobic, thus adding shine and slipperiness when applied to hair or skin. It forms a kind of barrier that prevents exogenous substances from entering the stratum corneum and at the same time prevents water loss. It is also UV-resistant, non-greasy and cost-effective. At low concentrations it is considered by the US FDA (Food and Drug Administration) to be a skin protector with a good degree of safety.

It is therefore considered safe when formulated to be non-irritating in cosmetic products as, given its high molecular weight, it is poorly absorbed by the skin or scalp.

PPG (Polypropylene glycol) in small quantities is a safe, biocompatible, biodegradable polymer that produces pyruvic acid, a metabolite that our body uses to produce metabolic energy.

And now let us talk about PEGs.

Since the PEG (Polyethylene glycol) family is very numerous and can be found in cosmetic, industrial, pharmaceutical, medical and other products, we need to make an introductory statement on the subject, which is rather complex from a safety point of view because these products not only come into contact with the skin, but, as in the case of medical products, are ingested.

PEGs (polyethylene glycol) polymerise condensed ethylene oxide and water and are referred to as polyethylene glycols, but are actually complex chemical components, polymers bonded together. For example, plastic is polyethylene and has a hard consistency, while polyethylene combined with glycol forms a liquid. PEGylation is produced not only as etherification, but also as transesterification, which is the transformation of an alcohol by an ester.

The number appearing after the abbreviation PEG represents the molecular weight and the higher this number is, the less it penetrates the skin.