Polyurethane-45 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.
- "-45" 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:
epsilon caprolactone, Trimethylolpropane, hexamethylene diisocyanate.
Description of raw materials used in production with their functions.
- Epsilon Caprolactone. A monomer that reacts to form a polyol via ring-opening polymerization, providing a flexible backbone for the polyurethane.
- Trimethylolpropane (TMP). A tri-functional alcohol providing three reactive sites, making it possible to create a crosslinked structure in the polymer.
- Cyclic trimer of hexamethylene diisocyanate. A diisocyanate that allows for the formation of urethane linkages in the polymer and imparts strength and stability to the polyurethane.
Step-by-step summary of industrial chemical synthesis process.
- Epsilon caprolactone is polymerized in the presence of Trimethylolpropane as an initiator to form a polyol.
- The resulting polyol is reacted with the cyclic trimer of hexamethylene diisocyanate to form a polyurethane prepolymer.
- The reaction proceeds until the final polyurethane polymer is formed.
What it is used for and where
Cosmetics
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.
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.
