Carbomer 941

Carbomer 941 – Crosslinked Polyacrylic Acid Gelling Agent for Cosmetics and Pharmaceuticals

Basic Information

• INCI Name: Carbomer

• CAS Number: 9003-01-4 (common), also 76050-42-5

• Appearance: White, fluffy powder

• Molecular Weight: High molecular weight polymer

• Carboxylic Acid Content: 56.0–68.0% (dried basis)

• Viscosity (0.5% neutralized aqueous dispersion): Typically lower than Carbomer 940, offering different rheology

• Solubility: Swells and disperses in water upon neutralization

• Storage: Store in a cool, dry place, protected from moisture and direct sunlight

Overview
Carbomer 941 is a high-molecular-weight crosslinked polyacrylic acid polymer similar to Carbomer 940 but with a different crosslinking density and rheological profile. It is produced by the polymerization of acrylic acid with crosslinking agents such as allyl ethers of pentaerythritol. The degree of crosslinking is optimized to provide a unique balance of viscosity, clarity, and flow properties, making Carbomer 941 suitable for applications where a lighter, less viscous gel is desired.

Key Differences from Carbomer 940
While both polymers are crosslinked polyacrylic acid thickeners, Carbomer 941 typically yields gels with lower viscosity at the same concentration, offering a smoother, less “short” flow. It is particularly suited for formulations where a softer texture, better clarity, or improved suspension of delicate particles is required.

Mechanism of Action
Like all carbomers, Carbomer 941 is supplied as a dry, acidic powder with tightly coiled polymer chains. When dispersed in water and neutralized with an alkaline agent (e.g., triethanolamine, sodium hydroxide), the carboxylic acid groups ionize, creating electrostatic repulsion that uncoils the polymer chains. This forms a three-dimensional hydrogel network that traps water, resulting in a clear, pseudoplastic gel. The rheology is pH-dependent and typically optimized in the range of 5–8.

Physicochemical Properties

• High clarity: Forms transparent gels that are visually appealing.

• Effective at low concentrations: Typically used at 0.2–0.6% for viscosity modification.

• Smooth texture: Provides a soft, elegant feel, suitable for sensitive skin applications.

• Excellent suspension: Suspends pigments, actives, and insoluble particles effectively.

• pH responsiveness: Requires neutralization for full thickening; works best at pH 5–8.

• Shear-thinning: Gels thin upon application, providing good spreadability.

Applications

• Cosmetics and personal care: Used in clear gels, serums, lotions, sunscreens, shaving gels, and hair styling products where a lighter texture and clarity are desired.

• Pharmaceuticals: Employed as an excipient in topical gels, ointments, and drug delivery systems.

• Other: Suitable for use in oral care products, household cleaners, and industrial formulations.

Recommended Use
Typical usage levels range from 0.2–0.6% of the formulation. Disperse the powder in water with agitation until fully hydrated, then neutralize with an alkaline agent (e.g., triethanolamine, sodium hydroxide, or aminomethyl propanol) to achieve the desired viscosity. Optimize based on specific formulation requirements.

Safety and Handling

• Generally recognized as safe for use in cosmetics and pharmaceuticals at recommended concentrations.

• Low irritation potential; well-tolerated by skin.

• Avoid inhalation of dust – use appropriate personal protective equipment (gloves, dust mask, safety goggles).

• Store in a cool, dry place, away from direct sunlight and moisture.

• Shelf life: typically 24 months under recommended storage conditions.

Quality Assurance
Each batch is tested for viscosity, carboxylic acid content, and clarity to ensure consistent performance.