Polyurethane-78 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.
• "-78" 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:

Soy Acid, phthalic anhydride, Pentaerythritol, SMDI, Saturated Methylene Diphenyl Diisocyanate.

Description of raw materials used in production with their functions.

• Soy Acid. Acid derived from soy, provides hydroxyl functional groups for urethane bond formation.
• phthalic anhydride. Used to modify soy, increasing its functionality and molecular weight.
• Pentaerythritol. Provides multiple hydroxyl groups for reaction with diisocyanate.
• SMDI (Saturated Methylene Diphenyl Diisocyanate). Provides isocyanate groups for urethane bond formation.
• Saturated Methylene Diphenyl Diisocyanate. Another diisocyanate used to form urethane bonds.

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

• Soy Acid is modified via esterification with phthalic anhydride and Pentaerythritol to obtain a modified polyol.
• The modified polyol is reacted with SMDI and Saturated Methylene Diphenyl Diisocyanate to form a polyurethane prepolymer with terminal isocyanate groups.
• The reaction is carried to completion to form 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.

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.