Polyquaternium-28
[CAS# 131954-48-8]

Identification

• Classification: Surfactant >> Cationic surfactant >> Quaternary ammonium salt type
• Name: Polyquaternium-28
• Synonyms: N,N,N-Trimethyl-3-((2-methyl-1-oxo-2-propenyl)amino)-1-propanaminium chloride polymer with 1-ethenyl-2-pyrrolidinone
• Molecular Formula: (C₆H₉NO)_n^.(C₁₀H₂₁N₂O)_n^.nCl
• CAS Registry Number: 131954-48-8
• EC Number: 603-542-1
• SMILES: CC(=C)C(=O)NCCC[N+](C)(C)C.C=CN1CCCC1=O.[Cl-]

Safety Data

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411

Discovory and Applicatios

Polyquaternium-28 is a cationic polyelectrolyte widely used in personal care products, particularly in hair care formulations, as a conditioning agent and film-former. Belonging to the polyquaternium family of quaternary ammonium polymers, it is characterized by its positive charge, which enables strong adhesion to negatively charged surfaces like hair and skin. Its development and applications are well-established in the literature, stemming from advancements in cationic polymer synthesis for cosmetic and industrial uses.

The discovery of polyquaternium-28 is rooted in the evolution of quaternary ammonium polymers, which began gaining attention in the mid-20th century for their surfactant and conditioning properties. The polyquaternium class, standardized by the International Nomenclature of Cosmetic Ingredients, emerged in the 1970s as the cosmetic industry sought polymers with enhanced substantivity, conditioning, and formulation compatibility. Polyquaternium-28, a copolymer typically composed of vinylpyrrolidone and methacrylamidopropyltrimonium chloride, was developed to provide superior conditioning, detangling, and film-forming properties, particularly for hair care products. Its introduction addressed the need for polymers that could improve hair manageability and aesthetics under varying environmental conditions. Progress in controlled radical polymerization and quaternization techniques during the 1960s and 1970s facilitated the precise synthesis of such polymers, allowing tailored charge density and molecular weight.

Chemically, polyquaternium-28 consists of a backbone incorporating vinylpyrrolidone, which contributes to film-forming and moisturizing properties, and methacrylamidopropyltrimonium chloride, which provides cationic quaternary ammonium groups. The positive charge enhances electrostatic interactions with negatively charged hair surfaces, while the hydrophilic nature ensures solubility in aqueous formulations. The polymer’s high molecular weight and balanced cationic character enable it to form a smooth, protective coating on hair strands. Synthetically, it is produced via free-radical copolymerization of the monomers in an aqueous or solvent-based medium, using initiators such as ammonium persulfate or azobisisobutyronitrile. The quaternized monomer is incorporated to achieve the desired cationic charge density, and reaction conditions are controlled to optimize molecular weight and polydispersity. These processes are grounded in established polymer chemistry techniques, ensuring consistent quality and performance.

The primary application of polyquaternium-28 is in hair care products, including shampoos, conditioners, and styling aids. Its cationic nature allows it to bind effectively to the negatively charged keratin of hair, reducing static, improving wet and dry combability, and enhancing shine and softness. The polymer forms a thin, flexible film on hair, which helps protect against environmental damage, such as humidity and heat, and provides detangling benefits. It is particularly valued in rinse-off conditioners, where it delivers conditioning without excessive buildup, and in leave-in products, where it enhances manageability and styling hold. In skin care, polyquaternium-28 is used in moisturizers and cleansers to improve skin feel and hydration, leveraging its film-forming and humectant properties. Its compatibility with a wide range of surfactants and formulation ingredients makes it a versatile component in cosmetic products.

Beyond cosmetics, polyquaternium-28 has been explored in pharmaceutical applications, such as topical drug delivery systems, where its adhesion and film-forming properties aid in controlled release and skin contact. In academic research, it is studied for its interactions with biological surfaces, polymer-surfactant dynamics, and environmental behavior. The cationic nature of polyquaternium-28 raises concerns about its persistence in aquatic environments, prompting investigations into its biodegradability and ecotoxicity to ensure sustainable use. Commercially, it is supplied by companies like Ashland and Lubrizol as aqueous solutions or dispersions, designed for easy incorporation into formulations.

The significance of polyquaternium-28 lies in its ability to deliver exceptional conditioning and aesthetic benefits in personal care products. Its development reflects advancements in polymer synthesis, enabling the creation of high-performance cationic polymers tailored for cosmetic applications. By improving hair and skin care formulations, it has become an essential component in the personal care industry, with ongoing research focused on optimizing its performance and environmental profile.

References

1996. Protein stabilisation using additives based on multiple electrostatic interactions. Developments in Biological Standardization
PMID: 8854019

2000. S13 | EUCOSMETICS | Combined Inventory of Ingredients Employed in Cosmetic Products (2000) and Revised Inventory (2006). Zenodo
DOI: 10.5281/zenodo.2624118