Polyurethane-9 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.
- "-9" 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:
Adipic acid, toluene diisocyanate, propylene glycol, ethylene glycol, hydroxyethyl acrylate monomers.
Description of the raw materials used in production and their functions.
- Adipic acid. A dicarboxylic acid used as a diacid component to form polyester segments in polyurethanes.
- Toluene diisocyanate. An aromatic diisocyanate used as a cross-linking agent to form the polyurethane backbone through isocyanate reactions.
- Propylene glycol. An aliphatic diol that provides soft segments to the polymer contributing to its flexibility.
- Ethylene glycol. Similar to propylene glycol, it's another aliphatic diol helping to provide soft segments to the polyurethane.
- Hydroxyethyl acrylate monomers. Monomers that provide reactive functional groups that can be further polymerized in the presence of other reactive agents.
Step-by-step industrial synthesis.
- Preparation. Adipic acid, Propylene glycol, and Ethylene glycol are mixed to form a polyester prepolymer.
- Reaction. Toluene diisocyanate is added to the polyester prepolymer, thus forming a polyurethane prepolymer structure.
- Extension. Hydroxyethyl acrylate monomers are then added, which react further to extend the polymer chain.
- Curing. The mixture is left to cure to ensure complete reaction and obtain the desired polyurethane.
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.
Nail sculpting. This ingredient is used in the extension and modification of the natural nail.
Film-forming agent. It produces a continuous ultra-thin film with an optimal balance of cohesion, adhesion and stickiness on the skin or hair to counteract or limit damage from external phenomena such as chemicals, UV rays and pollution.
CAS: 69011-31-0
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.
