Polyquaternium-33
[CAS# 69418-26-4]

Identification

• Classification: Catalysts and additives >> Polymer
• Name: Polyquaternium-33
• Synonyms: N,N,N-Trimethyl-2-[(1-oxo-2-propenyl)oxy]ethanaminium chloride polymer with 2-propenamide
• Molecular Formula: (C₈H₁₆ClNO₂)_x^.(C₃H₅NO)_x
• CAS Registry Number: 69418-26-4
• EC Number: 934-851-2

Safety Data

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Eye irritation	Eye Irrit.	2	H319

Discovory and Applicatios

Polyquaternium-33 is a synthetic cationic polymer used primarily in personal care and cosmetic products. It belongs to a broad class of compounds known as polyquaterniums, which are polymers bearing quaternary ammonium groups. These positively charged groups enable the polymer to bind effectively to negatively charged surfaces such as skin, hair, and fibers, making it useful as a conditioning agent, antistatic agent, and film former.

Polyquaternium-33 is synthesized through the polymerization of quaternary ammonium-containing monomers. The specific monomers and molecular structure may vary slightly depending on the manufacturer, but the defining feature is the presence of repeating units with quaternary ammonium side chains that impart a permanent positive charge. This cationic character allows the polymer to adhere strongly to biological surfaces that naturally carry a negative charge.

The discovery and development of polyquaterniums, including Polyquaternium-33, arose from the need for improved performance ingredients in the formulation of hair care and skin care products. Early quaternary ammonium compounds were known for their conditioning and antistatic properties, but they lacked the substantivity and durability offered by polymeric forms. By incorporating these groups into a polymer backbone, formulators achieved longer-lasting effects and improved compatibility with other cosmetic ingredients.

Polyquaternium-33 is particularly valued in hair care products such as shampoos, conditioners, and styling products. Its primary functions are to reduce static electricity, enhance detangling, and improve manageability. The polymer forms a thin film on the surface of the hair shaft, which helps to smooth the cuticle, reduce frizz, and impart a soft feel. Because of its film-forming properties, it also contributes to style retention in hair gels and sprays.

In skin care formulations, Polyquaternium-33 can act as a skin-conditioning agent. It forms a breathable film that helps retain moisture while giving the skin a smooth, non-greasy texture. It may also enhance the spreadability and sensory characteristics of creams and lotions.

Beyond personal care, Polyquaternium-33 has found application in textiles and fabric care, where it is used to impart softness and antistatic properties to synthetic fibers. In these applications, the polymer helps reduce static cling and improve the tactile feel of treated fabrics.

The polymer is typically used at low concentrations in formulations, usually ranging from 0.1% to 2%, depending on the desired effect and product type. It is compatible with a wide range of surfactants and other formulation ingredients, making it versatile and easy to incorporate into various product types.

Toxicological evaluations and safety assessments have shown that Polyquaternium-33 is generally well-tolerated when used in rinse-off and leave-on products. It is not known to be a skin sensitizer or significant irritant at normal use concentrations. Regulatory agencies and expert panels have included it in inventories of safe cosmetic ingredients, and it is widely permitted for use in cosmetics in many regions worldwide.

In summary, Polyquaternium-33 is a synthetic cationic polymer developed for use in cosmetic and personal care products. Its ability to form conditioning, antistatic films on hair and skin makes it valuable in a variety of formulations, from shampoos and conditioners to skin creams and styling aids. Its safety profile and formulation versatility support its continued widespread use in consumer products.