Sodium Polyglutamate, identified by its CAS number 28829-38-1, is a unique polymer with a distinct chemical profile that underpins its wide range of applications, particularly in the cosmetic and personal care sectors. Understanding its chemical properties—such as purity, appearance, and solubility—is crucial for formulators aiming to leverage its full potential. Typically supplied as a white crystalline powder, its high purity, often exceeding 99%, ensures consistent performance and efficacy in finished products.

Chemically, Sodium Polyglutamate is the sodium salt of polyglutamic acid, a homopolymer composed of glutamic acid units linked by peptide bonds. These bonds, specifically the amide linkages between the alpha-amino group of one glutamic acid and the gamma-carboxyl group of another, form the backbone of this biopolymer. The presence of numerous hydrophilic groups along its structure is responsible for its exceptional hygroscopic nature, allowing it to bind and retain significant amounts of water.

The physical properties of Sodium Polyglutamate are as follows: it appears as a white or off-white powder or granules. While soluble in water, its precise solubility can depend on factors like molecular weight and specific formulation conditions. The pH of a 1% solution typically falls within the 5.0-7.5 range, indicating a near-neutral to slightly acidic character, which is highly compatible with skin and hair pH levels.

The primary application of high purity Polyglutamate Sodium is as a potent moisturizing agent and humectant in skincare. Its ability to form a breathable film on the skin's surface not only hydrates but also protects the skin barrier. This results in long-lasting moisturizing effects, improved skin elasticity, and a smoother texture. Its capacity to inhibit melanin biosynthesis also presents opportunities for skin-brightening formulations.

In hair care, it functions effectively as a hair conditioning agent, enhancing moisture retention and imparting softness and shine to the hair strands. Its film-forming capability provides a protective coating that reduces damage and improves manageability. The biodegradable nature of this fermentation produced biopolymer further enhances its appeal in a market increasingly focused on sustainability.

Beyond cosmetics, similar polyglutamic acid derivatives find uses in other fields, though Sodium Polyglutamate's primary commercial focus remains personal care. Its robust chemical structure, combined with its natural origin and high purity, makes it a valuable ingredient for formulators seeking advanced performance and a clean ingredient profile. As research continues, the full spectrum of its chemical capabilities and applications is likely to expand further.