Sodium Polyaspartate is a chemical compound, saline form of a synthetic polymer derived from the amino acid aspartic acid.

The name describes the structure of the molecule

• "Sodium" indicates the presence of sodium ions in the compound.
• "Polyaspartate" refers to a polymer derived from aspartic acid, an amino acid. "Poly" indicates that there are multiple units of aspartate linked together in a chain.

Description of raw materials used in production

• Aspartic Acid - An amino acid.
• Sodium Hydroxide (NaOH) - To convert the polyaspartic acid into its salt form, sodium polyaspartate.

Step-by-step summary of industrial chemical synthesis process

• Polymerization - Aspartic acid undergoes thermal polymerization, often in the presence of a catalyst, to form polyaspartic acid.
• Neutralization - The polyaspartic acid is then neutralized with sodium hydroxide to form sodium polyaspartate.
• Purification - The resulting product is purified to remove any impurities and unwanted by-products.
• Drying - The purified product is dried to remove residual water.
• Quality Control - A quality check is performed to ensure that the sodium polyaspartate meets the desired specifications.

What it is for and where

Cosmetics

Hair conditioning agent. A significant number of ingredients with specific and targeted purposes may co-exist in hair shampoo formulations: cleansers, conditioners, thickeners, matting 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, dispersants that may contain cationic surfactants, thickeners, emollients, polymers. The typology of hair conditioning agents includes: intensive conditioners, instant conditioners, thickening conditioners, drying conditioners. They can perform their task generally accompanied by other different ingredients.

Humectant. Hygroscopic compound used to minimise water loss in the skin and to prevent it from drying out by facilitating faster and greater absorption of water into the stratum corneum of the epidermis.  The epidermis is the most superficial of the three layers that make up human skin (epidermis, dermis and hypodermis) and is the layer that maintains hydration in all three layers. In turn, the epidermis is composed of five layers: horny, the most superficial, granular, spinous, shiny, and basal. Humectants have the ability to retain the water they attract from the air in the stratum corneum and have the function of moisturising the skin. They are best used before emollients, which are oil-based.

Skin conditioning agent. It is the mainstay of topical skin treatment as it has the function of restoring, increasing or improving skin tolerance to external factors, including melanocyte tolerance. The most important function of the conditioning agent is to prevent skin dehydration, but the subject is rather complex and involves emollients and humectants that can be added in the formulation.

Commercial applications

Toothpaste. Used to prevent the formation of dental stains (1).

Cosmetics. Used as a moisturizing and conditioning agent in skincare and haircare  and as an anti-aging agent (2).

Haircare Products. Added to conditioners and treatments to enhance hair texture and manageability.

Detergents. Leveraged for its chelating properties, which help bind minerals in water, preventing scale formation.

Environmental Protection. Used in products to protect materials such as cement and metal from corrosion.

Agriculture. Added to fertilizers to improve water retention and nutrient uptake in soil (3).

• Molecular Formula  C₄H₅NNa₂O₄
• Molecular Weight  177.07 g/mol
• CAS  94525-01-6
• UNII    48MC6MXP9X
• EC Number

References_____________________________________________________________________

(1) Jowett AK, Marlow I, Rawlinson A. A double blind randomised controlled clinical trial comparing a novel anti-stain and calculus reducing dentifrice with a standard fluoride dentifrice. J Dent. 2013 Apr;41(4):313-20. doi: 10.1016/j.jdent.2012.12.005.

(2) Yu, H. G., Ji, H. G., Kim, J. D., & Jang, H. I. (2019). New Anti-Aging and Anti-Wrinkle Material: Properties and Activities of Nanoparticle Containing Poly (Aspartic Acid) Derivatives. Journal of Nano Research, 59, 57-76.

Abstract. Polymers such as sodium polyacrylate; polysaccharides in starch; polyamino acids, which are the products of alpha-amino acid condensation; and polypeptides are widely used in cosmetics and pharmaceuticals. They are used as viscosity agent, emulsifying agent, and carriers for drug delivery. However, we studied the function of polymers as activity agent, especially that of synthesized poly(aspartic acid). Poly(aspartic acid) is a biocompatible synthetic polymer. It is a water-soluble polyamide containing carboxylic pendants prepared from polysuccinimide, the polycondensate of aspartic acid monomer, by hydrolysis. In this study, we prepared poly(aspartic acid) derivatives conjugated with L-lysine or L-lysine and other materials. The chemical structure of these polymers was confirmed by FT-IR and 1H-NMR spectroscopy. Moreover, these novel poly(aspartic acid) derivatives stimulated typeⅠcollagen biosynthesis and inhibited MMP-1(collagenase) activity. We could conclude that the microfludization process improved skin permeability and confirmed better permeability than that achieved with existing nano emulsions.

(3) Kumar, A. (2012). Polyaspartic Acid–A Versatile Green Chemical. Chem. Sci. Rev. Lett, 1(3), 162-167.