Polyurethane-67 is an inorganic chemical compound, a segmented block copolymer derived from urethane and synthesised from isocyanates.
The name describes the structure of the molecule:
- "Polyurethane" is a term that describes a class of polymers widely used in various applications due to their versatility and desirable properties such as durability, flexibility and abrasion resistance and temperature variations.
- "-67" is a reference to the specific type or grade of polyurethane, which can be characterized by such factors as the types of isocyanates and polyols used, their relative amounts, and the presence of any additives. . This is a designation used to differentiate different molecular structures or variants of the polymer. In cosmetic chemistry, these numbers can help formulators identify specific characteristics or behaviors of a given ingredient, particularly when a chemical family has multiple derivatives or forms.
Significant substances used in the production method:
hexamethylene diisocyanate (HDI isocyanurate trimer), PPG-3 Butyl Ether, epsilon-caprolactone, valerolactone, Decyl Alcohol, N-(3-aminopropyl)imidazole.
Description of the raw materials used in production and their functions.
- Hexamethylene diisocyanate (HDI isocyanurate trimer). A trimerized form of HDI used as a cross-linking agent in polyurethane production. Enhances the thermal and mechanical resilience of the polymer.
- PPG-3 Butyl Ether (Polypropylene glycol butyl ether). A polyol that contributes to the flexibility and elastomeric behavior of the polyurethane.
- Epsilon-caprolactone. A monomer that, once polymerized, provides flexible segments to the polyurethane, enhancing its toughness and flexibility.
- Valerolactone. Another monomer that provides flexible segments in the polyurethane, similar to epsilon-caprolactone.
- Decyl Alcohol. A fatty alcohol used to modify the properties of polyurethane, such as plasticizing and compatibility with other materials.
- N-(3-aminopropyl)imidazole. A catalyst that speeds up the reaction between isocyanates and polyols.
Step-by-step industrial synthesis.
- Preparation. Mix PPG-3 Butyl Ether with epsilon-caprolactone and valerolactone.
- Reaction. Add hexamethylene diisocyanate (HDI isocyanurate trimer) to the mixture and initiate the polyurethane-forming reaction.
- Modification. Introduce Decyl Alcohol to adjust polyurethane properties.
- Catalysis. Add N-(3-aminopropyl)imidazole to accelerate the polymerization reaction.
- Curing. The mixture is left to cure to ensure complete reaction and obtain the desired polyurethane
What it is used for and where
Cosmetics
Surface modifier. Substance that has the property of preventing superficial defects in the epidermis by repelling oils and water and of giving the skin greater resistance against blemishes.
It appears as a white powder or colorless liquid.
Safety
Urethane (also called ethyl carbamate) is a by-product of fermentation 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.
