Polyurethane-85 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.
- "-85" 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:
- poly(1,4-butanediol)-28, poly(1,4-butanediol)-41, isopropylidendicyclohexanol, Isophorone Diisocyanate, 2-Hydroxyethyl Acrylate.
- Description of the raw materials used in production and their functions.
- poly(1,4-butanediol)-28 and poly(1,4-butanediol)-41 are polyols with specific molecular weights used to dictate the properties of the polyurethane, such as flexibility and durability.
- isopropylidendicyclohexanol. A cyclic diol used to extend the polymer chain and improve properties like thermal and chemical resistance.
- Isophorone Diisocyanate. A diisocyanate used to react with the polyols forming the polyurethane backbone.
- 2-Hydroxyethyl Acrylate. An acrylic monomer that introduces acrylic functionalities into the polymer, allowing further cross-linking or functionalization reactions.
Step-by-step industrial synthesis.
- Preparation. Initially, a mixture of the polyols poly(1,4-butanediol)-28 and poly(1,4-butanediol)-41 is prepared.
- Reaction. To this polyol blend, Isophorone Diisocyanate is then added to form a polyurethane prepolymer.
- Chain Extension. The isopropylidendicyclohexanol is then slowly added to further extend the polymer chain.
- Modification. Lastly, the 2-Hydroxyethyl Acrylate is added to the prepolymer to introduce the acrylic functionalities.
- Cross-linking. Depending on the application specifications, further cross-linking reactions may be performed.
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
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.
