Polysilicone-19 is a synthetic silicone-based polymer known for its film-forming, conditioning, and protective properties. It is primarily used in cosmetics and personal care products, including sunscreens, hair care products, and skin treatments. Polysilicone-19 forms a flexible, breathable film on the skin or hair, providing long-lasting protection and enhancing the efficacy of active ingredients. It is valued for its ability to create a smooth, non-greasy finish and for its water-resistant properties, making it ideal for formulations requiring durability.

Chemical Composition and Structure
Polysilicone-19 is a polysiloxane-based polymer, which means it consists of repeating siloxane (Si-O-Si) units combined with organic groups. This structure allows it to form a flexible, durable, and water-resistant film on the skin or hair. The siloxane backbone gives the compound its silicone properties, while the organic side chains enhance its compatibility with other ingredients in cosmetic formulations, making it a versatile component for creating stable emulsions and improving the feel of the product.

Physical Properties
Polysilicone-19 typically appears as a clear or slightly yellow, viscous liquid or gel. It is soluble in various organic solvents and can be dispersed in both oil- and water-based formulations. The polymer has excellent film-forming properties, creating a long-lasting, water-resistant barrier. It provides a smooth, soft texture to products without leaving a heavy or greasy residue, which is particularly beneficial in products such as sunscreens, foundations, and long-wear cosmetics.

Production Process
The production of Polysilicone-19 involves several steps:

1. Polymerization: Siloxane monomers undergo polymerization to form long chains of repeating siloxane units. The process is controlled to ensure the creation of a stable and flexible polymer.

2. Modification: Organic side chains are attached to the polymer to enhance its film-forming and conditioning properties, improving its ability to adhere to skin or hair.

3. Purification: The polymer is purified to remove any impurities or unreacted monomers, ensuring the final product is of high quality and suitable for cosmetic applications.

4. Formulation: The purified Polysilicone-19 is then incorporated into various cosmetic products, where it contributes to the durability, texture, and performance of the formulation.

Applications

• Sunscreens: Polysilicone-19 is commonly used in sunscreen formulations due to its water-resistant properties. It helps create a long-lasting protective barrier that remains on the skin even after exposure to water or sweat, enhancing the efficacy of UV filters.

• Hair Care: In hair care products, Polysilicone-19 forms a protective film around the hair shaft, improving smoothness, shine, and manageability. It helps protect the hair from environmental damage and moisture loss, making it ideal for conditioners, serums, and styling products.

• Makeup: Polysilicone-19 is used in makeup products like foundations and long-wear formulations due to its ability to create a smooth, even finish. It helps prolong the wear time of makeup, reducing smudging and fading throughout the day.

• Skincare: In skincare formulations, Polysilicone-19 acts as a film former and skin conditioning agent, providing a lightweight, non-greasy barrier that helps lock in moisture while protecting the skin from environmental stressors.

INCI Functions:

Hair conditioning agent. A large number of ingredients with specific purposes can co-exist in a hair shampoo: cleansers, conditioners, thickeners, mattifying agents, sequestering agents, fragrances, preservatives, special additives. However, the indispensable ingredients are the cleansers and conditioners as they are necessary and sufficient for hair cleansing and manageability. The others act as commercial and non-essential auxiliaries such as: appearance, fragrance, colouring, etc. Hair conditioning agents have the task of increasing shine, manageability and volume, and reducing static electricity, especially after treatments such as colouring, ironing, waving, drying and brushing. They are, in practice, dispersing agents that may contain cationic surfactants, thickeners, emollients, polymers. The typology of hair conditioners includes: intensive conditioners, instant conditioners, thickening conditioners, drying conditioners.

CAS: 887374-30-3

Environmental and Safety Considerations

Polysilicone-19 is generally considered safe for use in cosmetics and personal care products. It is non-irritating and non-sensitizing when applied topically, making it suitable for a variety of skin types. 

However, like other silicone-based polymers, Polysilicone-19 is not biodegradable, which raises environmental concerns, particularly regarding its accumulation in aquatic environments. Due to these concerns, efforts are being made to improve the sustainability of silicone-based ingredients through better waste management practices and the exploration of eco-friendly alternatives. 

References__________________________________________________________________________

Mahajan, A. (2016). Advancements in polymers used in hair care: a review. Int J Res Cosmet Sci, 6(1), 6-16.

Abstract. Polymeric materials gained rapid significance in professional cosmetics formulation due to their large variety of functions. They are critically important for the creation of modern cosmetics and personal-care products. Polymers used in hair care represents promising means as film formers in hair fixatives, emulsifiers in hair-colorants, conditioning agents for hair, thickeners, rheology modifiers and sun protection agents. In the present paper different polymers which are used in hair care are classified on the basis of their application, along with their examples and mechanism of action. 

Facuri, S., Howe, A., Kortemeier, U., Langer, S., Schwab, P., & Yang, B. (2016). How to tame the fro: ethnic care. South African Pharmaceutical and Cosmetic Review, 43(3), 42-46.

Abstract. Researchers from the global speciality chemicals company, Evonik have developed two materials to improve the appearance of hair. Their efforts are focused on the needs of Ethnic consumers, fulfilling specific claims and offering high performance ingredients.… Polysilicone-19 is a silicone UV quat containing side chains with either cationic groups or …According to Evonik, including polysilicone-19 in a rinse off product provides 40 per cent …