Ammonium Acryloyldimethyltaurate/Beheneth-25 Methacrylate Crosspolymer is a high-performance synthetic rheology modifier that creates elegant, “melting” cream-gel textures. It functions as a polymeric emulsifier capable of stabilizing high oil loads without the need for traditional surfactants, providing a velvety, non-sticky finish to skincare formulations.
- INCI Name:
- Ammonium Acryloyldimethyltaurate/Beheneth-25 Methacrylate Crosspolymer
- Chemical/Scientific Name:
- 2-Methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulfonic acid, monoammonium salt, polymer with ethoxylated docosyl 2-methyl-2-propenoate, crosslinked
- Common Aliases:
- Aristoflex HMB
| Category: | Texture Enhancers |
| Source Origin: | Synthetic |
| Comedogenic Rating: | 0 |
| Primary Industries: | Skincare, Sunscreens, Luxury Cosmetics |
| Solubility: | Water-dispersible (Swelling polymer) |
At a Glance: Properties & Effects
| Texture Enhancement: | |
| Formula Stability: | |
| Hydration: | |
| Irritation Risk: |
- Primary Benefits: Creates sophisticated sensory profiles, stabilizes emulsions without surfactants, offers superior spreadability, and remains stable across a wide pH range (4.0–9.0).
- Potential Risks: Viscosity may decrease in the presence of high electrolyte (salt) concentrations; potential for pilling if used in excessive amounts alongside other film-formers.
Biological Action & Cosmetic Profile
Structurally, this synthetic polymer is classified as an associative thickener. The molecule consists of a hydrophilic (water-loving) backbone with hydrophobic (oil-loving) side chains derived from Beheneth-25. When dispersed in Aqua, the polymer chains hydrate and expand into a three-dimensional network. The hydrophobic segments associate with oil droplets or other hydrophobic ingredients like Squalane and Caprylic Capric Triglyceride, effectively anchoring them within the aqueous matrix.
The chemical architecture allows for the creation of “Emulsifier-Free” cream-gels. Unlike traditional Carbomer variants, which require neutralization with a base like Sodium Hydroxide, this crosspolymer is pre-neutralized and ready to use. Upon application to the skin, the salt content in human sweat triggers a “break” in the polymer network. This rapid transition from a structured gel to a liquid state provides the characteristic “quick-break” or “melting” sensation, releasing water and humectants like Glycerin for an immediate cooling effect.
Beyond its rheological properties, the polymer contributes to the physical stability of complex formulations. It prevents the coalescence of oil droplets, ensuring that sunscreens and heavy creams remain homogeneous over time. The film left on the skin is matte and non-tacky, making it a preferred choice for formulations targeting oily or combination skin types that require moisture without a greasy residue.
Broader Applications & Origins
Manufacturing of this ingredient involves sophisticated polymer chemistry to ensure high purity and consistent viscosity. It was specifically developed to overcome the sensory limitations of older thickeners like Xanthan Gum, which can feel “slimy” or “stringy” at high concentrations. Because it can stabilize up to 20-30% oil phase without additional emulsifiers, it is frequently utilized in “minimalist” formulations to reduce the potential for skin irritation associated with traditional surfactants.
Routine Integration
- Synergies: Works exceptionally well with Panthenol, Allantoin, and various silicones like Dimethicone to enhance the “slip” of a product.
- Conflicts: High concentrations of electrolytes—such as those found in Sodium Ascorbyl Phosphate or certain mineral salts—can cause the polymer network to collapse, resulting in a loss of product thickness.
Clinical Consensus & Safety
The Cosmetic Ingredient Review (CIR) Expert Panel has evaluated the safety of acryloyldimethyltaurate polymers, concluding they are safe for use in cosmetics. Due to the very large molecular weight of these crosspolymers, they are unable to penetrate the stratum corneum, precluding any systemic toxicity. Clinical testing indicates they are non-irritating and non-sensitizing, even when used in leave-on products at concentrations up to 2%. Formulations containing this polymer are generally suitable for sensitive skin because the ingredient itself is inert and lacks the skin-disrupting potential of low-molecular-weight surfactants.
Is this ingredient a microplastic?
While it is a synthetic polymer, it is typically used in a crosslinked form that swells in water rather than existing as solid, non-degradable particles. However, regulatory definitions of microplastics are evolving, and its status depends on specific regional environmental frameworks.
Will this ingredient cause my skincare to pill?
Pilling usually occurs if the product is applied too thickly or over incompatible oil-based serums. This polymer is designed to minimize pilling compared to standard carbomers, but layering it with heavy silicones or other film-forming polymers can sometimes result in friction-induced flaking.
Is it safe for acne-prone skin?
Yes. It has a comedogenic rating of 0 and is often used in “oil-free” gel moisturizers specifically formulated for acne-prone skin because it provides texture without using pore-clogging waxes or heavy oils.