Polyurethane-91 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.
- "-91" 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:
polyester, Hexanediol, Dimethyl Carbonate, 3-dimethylamino-1,2-propanedio, 1,4-Butanediol, Isophorone Diisocyanate, Lactic Acid.
Description of the raw materials used in production and their functions.
- Polyester. A polymer made up of esters, typically used as the primary component in the polyol system for the mechanical and thermal properties of polyurethane.
- Hexanediol. An aliphatic diol used to enhance the flexibility of polyurethane.
- Dimethyl Carbonate. A carbonate used as a plasticizing agent and rheology modifier in polyurethane.
- 3-dimethylamino-1,2-propanediol. A functional chemical that can act as a catalyst or regulator of polyurethane properties.
- 1,4-Butanediol. A diol used for chain building and regulating the flexibility of polyurethane.
- Isophorone Diisocyanate. An aliphatic diisocyanate used as a cross-linking agent in polyurethane.
- Lactic Acid. An organic acid that can act as a pH regulator or modifier agent.
Step-by-step industrial synthesis.
- Preparation. Polyester, Hexanediol, and 1,4-Butanediol are mixed to form a polyol base.
- Reaction. Isophorone Diisocyanate is added, initiating the formation of polyurethane.
- Modification. Dimethyl Carbonate, 3-dimethylamino-1,2-propanediol, and Lactic Acid are introduced to modulate polyurethane properties.
- Curing. The mixture is left to cure to ensure complete reaction and obtain the desired polyurethane.
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.
