Polyurethane-47 is an inorganic chemical compound, an urethane and Dimethicone by-product.

Description of raw materials used in production and their functions.

• Polyester polyol. Used as the main component, it forms the backbone of the polymer.
• Isophorone diisocyanate (IPDI). Acts as crosslinking agents and provides the necessary reactivity for polymer formation.
• Bis-hydroxypropyl dimethicone. Acts as a flexibilizer and modifies the surface properties of the polymer.

Step-by-step summary of industrial chemical synthesis process.

• The polyester polyol is initially reacted with IPDI.
• Following the formation of the prepolymer, the bis-hydroxypropyl dimethicone is then introduced.
• The reaction proceeds until the desired polymer, i.e., Polyurethane-47, is formed.

What it is for and where

Cosmetics

Film-forming agent. It produces, upon application, a very thin continuous film with an optimal balance of cohesion, adhesion and stickiness on skin, hair or nails to counteract or limit damage from external phenomena such as chemicals, UV rays and pollution.

It appears as a white powder or colorless liquid.

Safety

Dimethicone ((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.

Urethane (also called ethyl carbamate) is a fermentation by-product and is considered a genotoxic agent.

Polyurethanes are rather complex, inert and biostable materials that are also used in biomedical applications. They are typically synthesised by the reaction of a glycol or polyol with polyisocyanate or diisocyanate. It is known that exposure to isocyanates can cause asthma, contact allergies, conjunctival and skin irritation. However, a study by the Cosmetic Ingredient Review Expert Panel in 2017 found that the rates of harmful residues are not significant for human health.