Polyurethane-88 is an inorganic chemical compound, an urethane and Dimethicone by-product. Significant substances used: polyester, Epsilon-Caprolactone, hexamethylene carbonate, Neopentyl Glycol, Bis-Hydroxypropyl Dimethicone, HEMA.
Description of raw materials used in production and their functions.
- Epsilon-Caprolactone. A monomer that, when polymerized, produces an aliphatic polyester.
- Hexamethylene carbonate. Crosslinking agent used in the formation of the polyester.
- Neopentyl Glycol. Acts as a chain extender component to improve the thermal properties of the polymer.
- Bis-Hydroxypropyl Dimethicone. Modifies the surface properties of the polymer and acts as a flexibilizer.
- Isophorone Diisocyanate (IPDI). Crosslinking agent providing the necessary reactivity for polymer formation.
- HEMA (Hydroxyethyl Methacrylate). Used to "cap" the polymer, enhancing its properties and making it more reactive to binders.
Step-by-step summary of industrial chemical synthesis process.
- Begin with the reaction of Epsilon-Caprolactone with hexamethylene carbonate to form a polyester.
- Once the polyester is obtained, a mixture of this polyester with Neopentyl Glycol and Bis-Hydroxypropyl Dimethicone is prepared.
- IPDI is then introduced and the reaction proceeds to form the urethane polymer.
- Finally, the urethane polymer is "capped" with HEMA to yield Polyurethane-88.
What it is used for and where
Cosmetics
Binder agent. Ingredient that is used in cosmetic, food and pharmaceutical products as an anti-caking agent with the function of making the product in which it is incorporated silky, compact and homogenous. The binder, either natural such as mucilage, gums and starches or chemical, may be in the form of a powder or liquid.
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.
