Polyurethane-7 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.
• "-7" 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:

Hexylene Glycol, Neopentyl Glycol, Adipic Acid, isophorone diisocyanate, dimethylolpropanoic acid monomers.

Description of raw materials used in production with their functions.

• Hexylene Glycol. An alcohol that provides hydration and solubility to formulations.
• Neopentyl Glycol. Provides moisture resistance and enhances thermal stability.
• Adipic Acid. A type of dicarboxylic acid that enhances flexibility and durability.
• Isophorone diisocyanate (IPDI). A diisocyanate used to provide weather resistance and light stability.
• Dimethylolpropanoic Acid. Provides functional groups for reaction with isocyanates.

Step-by-step summary of industrial chemical synthesis process.

• Hexylene Glycol, Neopentyl Glycol, and Adipic Acid are reacted to form a polyol.
• This polyol is then reacted with Isophorone diisocyanate and Dimethylolpropanoic Acid to form a polyurethane prepolymer.
• The polyurethane prepolymer is then chain extended to form the final polyurethane polymer.

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.