Polyurethane-90 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.
• "-90" 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, methylpentanediol, Diethyl Carbonate, Neopentyl Glycol, Isophorone Diisocyanate, HEMA.
• Description of the raw materials used in production and their functions.
• Hexanediol. An aliphatic diol used to enhance the flexibility of polyurethane.
• Methylpentanediol. Another diol used to adjust the properties of the polyurethane.
• Diethyl Carbonate. A carbonate used as a plasticizing agent and rheology modifier in polyurethane.
• Neopentyl Glycol. A diol used to improve the thermal stability and mechanical properties of polyurethane.
• Isophorone Diisocyanate. An aliphatic diisocyanate used as a cross-linking agent in polyurethane.
• HEMA (2-Hydroxyethyl methacrylate). An acrylic monomer used to introduce reactive functional groups into the polyurethane.

Step-by-step industrial synthesis.

• Preparation. Hexanediol, Methylpentanediol, and Neopentyl Glycol are mixed to form a polyol base.
• Reaction. Isophorone Diisocyanate is added, initiating the formation of polyurethane.
• Modification. Diethyl Carbonate and HEMA are introduced to modulate polyurethane properties and introduce reactive functional groups.
• Curing. The mixture is left to cure to ensure complete reaction and obtain 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.