Formulation of synthetic polymers in the cosmetic industry

Cosmetics can be divided into various categories comprising several types of products:

• skincare products (moisturizing, anti-wrinkle, anti-aging, slimming, anti-spot, firming, etc.);

• make-up products for the eyes (mascaras, liners, etc.), face (foundations, powders, etc.), nails (nail polish) and lips (lipstick and lip gloss);

• suncare products (protection, self-tanners, etc.) ;

• personal hygiene products (soaps, showers, baths, depilatories, deodorants, etc.);

• hair care products (shampoos, colorants, dyes, perms, anti-hair loss lotions, hairsprays, lacquers);

• perfumes or hydroalcohols (extracts, eau de toilette, eau de parfum, etc.).

Commercial products are formulations made by mixing, combining or shaping numerous natural or synthetic ingredients, in a variety of preparations including emulsions, multiphase systems, solutions, gels, fat blends, powder blends, aerosols and new product forms (patches).

For many years, natural polymers in the form of gums and resins have been used in the cosmetics industry as water-soluble binders, thickeners and film-forming agents. However, polymers isolated from natural sources have a number of drawbacks: they vary in purity and quality, and are relatively expensive compared with common synthetic polymers. Other problems linked to difficulties in securing a stable supply, combined with viscosity variations and microbial contamination, have led to their substitution by synthetic or semi-synthetic polymers. Initially, semi-synthetic polymers, which are modified natural polymers, and synthetic polymers were developed to have properties identical to gums and resins. Today, polymers serve multiple purposes in cosmetic formulations. They are used :

• as film-forming agents in hair fixatives, mascara and nail polish;

• as thickeners and rheology modifiers in emulsions, gels, hair dyes and relaxers;

• as emulsifiers in lotions, sun creams and hair dyes;

• as conditioners, moisturizers, emollients, dispersants and water-resistant products.

The industry is constantly striving to improve formulations, adopting synthesis protocols based on an understanding of the molecular interactions between polymers and the other components of a skincare product.