Polyurethane-34 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.
- "-34" 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:
Hexanediol, Neopentyl Glycol, Adipic Acid, hexamethylene diisocyanate, N-(2-aminoethyl)-3-aminoethanesulfonic acid, ethylenediamine.
Description of raw materials used in production with their functions.
- Hexanediol. A polyol contributing to flexibility and mechanical properties of the polyurethane.
- Neopentyl Glycol. Another polyol aiding in enhancing thermal stability and mechanical properties.
- Adipic Acid. A dicarboxylic acid used to provide hydroxyl functional groups in polyurethane formation.
- Hexamethylene diisocyanate. A diisocyanate acting as a cross-linking agent, forming urethane bonds.
- N-(2-aminoethyl)-3-aminoethanesulfonic acid. Used as a neutralizing and stabilizing agent in polyurethane dispersions production.
- Ethylenediamine. A crosslinking and chain-extending agent.
Step-by-step summary of industrial chemical synthesis process.
- Hexanediol, Neopentyl Glycol, and Adipic Acid are reacted together to form a polyester with hydroxyl terminal groups.
- The polyester is then reacted with hexamethylene diisocyanate to form a polyurethane prepolymer.
- N-(2-aminoethyl)-3-aminoethanesulfonic acid is then added as a neutralizing agent.
- Lastly, Ethylenediamine is introduced to extend the polymer chain, forming 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.
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.
