Polyurethane-79 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 - Indicates that the molecule belongs to the polyurethane family, polymers formed by the reaction between a diisocyanate and a diol.
• 79  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:

hydrogenated polybutanediol, 1,6-Hexamethylene Diisocyanate, Hydrogenated Dilinoleyl Alcohol, 1,4-Butanedio, Stearyl Alcohol.

To exemplify:

Description of the raw materials used in production:

• Diisocyanates - Diisocyanates are chemical compounds used as reagents in the synthesis of polyurethane. Common diisocyanates used in the production include toluene diisocyanate (TDI) or diphenylmethane diisocyanate (MDI). These diisocyanates react with polyols to form the polyurethane structure.
• Polyols - Polyols are chemical compounds containing hydroxyl (OH) groups that react with diisocyanates to form the polyurethane structure. Common polyols used in the production include polyether polyols or polyester-based polyols. These polyols impart elasticity and strength.
• Crosslinking agents - Crosslinking agents are used to provide this polyurethane with its three-dimensional structure and desired physical properties. Crosslinking agents can be physical crosslinking agents, such as chemical crosslinkers like trifunctional polyols or crosslinking catalysts.

The synthesis process takes place in several stages:

• Preparation of monomers by reaction of a diisocyanate with a polyol. Diisocyanate is a compound that contains two groups of isocyanate (-NCO), and polyol is a molecule with multiple hydroxyl groups (-OH).
• Polymerization. Monomers react to form polyurethane by reacting diisocyanate isocyanate groups with polyol hydroxyl groups. This reaction forms urethane bonds (-NHCOO-) and causes the formation of polyurethane polymer.
• Processing to form the desired product with various techniques such as molding, casting or extrusion, depending on the desired shape of the final product.

It appears as a white powder or colorless liquid.

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.
• Surfactant - Suspending agent. Cosmetic or pharmaceutical suspensions are known to be thermodynamically unstable and it is therefore essential to include in the formulation a suspending agent capable of dispersing any sedimented particulates and reducing the rate of sedimentation. The presence of this agent increases the consistency of the suspension medium and exerts a protective colloidal action with a surfactant action.
• Viscosity control agent. It controls and adapts, Increasing or decreasing, viscosity to the required level for optimal chemical and physical stability of the product and dosage in gels, suspensions, emulsions, solutions. 

Safety

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.

Urethane (also called ethyl carbamate) is a by-product of fermentation and is considered a genotoxic agent.