Polyurethane-44 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.
- "-44" 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:
hexanedioic acid, hexamethylene diisocyanate (HDI), trimethylolpropane, 3-methyl-1,5-pentanediol (MPD), caprolactone monomers.
Description of raw materials used in production with their functions.
- Hexanedioic Acid (Adipic Acid). A dicarboxylic acid providing acid groups for ester and urethane bond formation.
- Hexamethylene Diisocyanate (HDI). Provides isocyanate groups for urethane bond formation.
- Trimethylolpropane (TMP). Trihydric alcohol providing hydroxyl groups for urethane and ester bond formation.
- 3-Methyl-1,5-Pentanediol (MPD). Dihydric alcohol used to provide hydroxyl and ester groups.
- Caprolactone. Cyclic monomer participating in the formation of polyester urethanes through ring-opening.
Step-by-step summary of industrial chemical synthesis process.
- Mixing: hexanedioic acid, trimethylolpropane, 3-methyl-1,5-pentanediol and caprolactone.
- Hexamethylene diisocyanate (HDI) is added to the mixture and allowed to react.
- Once a prepolymer is formed, polymerization continues until the desired degree is reached.
- Once a certain degree of polymerization is reached, the reaction is stopped and the polymer is cooled to obtain Polyurethane-44.
What it is used for and where
Cosmetics
Anticaking agent. This compound facilitates free flow and prevents aggregation or clumping of substances in a formulation by reducing the tendency of certain particles to stick together.
Bulking agent. It regulates the water content, dilutes other solids, can increase the volume of a product for better flow, acts as a buffer against organic acids, helps to keep the pH of the mixture within a certain level.
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.
