Acrylates copolymer is a group of chemical compounds containing methacrylic and acrylic acid monomers or any of their salts or esters. 

Acrylates Copolymer is a synthetic copolymer derived from the polymerization of acrylic acids and their derivatives. It is widely used in cosmetics and personal care products for its film-forming, emulsifying, and stabilizing properties. Due to its versatility, Acrylates Copolymer can be found in a broad range of formulations, including makeup products, hair care products, and skincare lotions.

Chemical Composition and Structure

Acrylates Copolymer is made from a combination of acrylic and methacrylic monomers, which form a polymer that can create a durable and flexible film on the surface of the skin or hair. Its polymer structure allows it to form waterproof films or improve the texture of a formulation, making products more stable and long-lasting.

Physical Properties

Acrylates Copolymer typically appears as a fine powder or viscous, colorless to whitish liquid, soluble in water or organic solvents depending on the formulation. It is valued for its ability to form transparent, durable films, which make cosmetic products longer-lasting and water-resistant—particularly useful in products like mascara, foundation, and sunscreens.

Production Process

The copolymer is produced through the polymerization of acrylic or methacrylic monomers, creating a polymer chain that can be modified to offer various properties such as elasticity or water resistance. The production process allows for tailoring the copolymer's characteristics to suit different cosmetic formulations.

The name defines the structure of the molecule:

• "Acrylates" are the salts, esters and conjugate bases of acrylic acid and its derivatives. They are commonly found in coatings, inks, adhesives, and a variety of other industrial and consumer products.
• "copolymer" is a polymer derived from several species of monomer. Polymerization of different types of monomers produces a copolymer, which may have properties not obtainable with a single type of monomer.

The process of synthesis of acrylic copolymers takes place in several stages:

• Preparation of monomers: The first phase of the synthesis of acrylate copolymer is the preparation of monomers. It is usually the reaction of acrylic acid or its derivatives with an alcohol or amine suitable for forming the acrylate monomer.
• Polymerization: Monomers are then polymerized to form copolymer using various polymerization techniques, such as free radical polymerization, which is most commonly used for the synthesis of acrylate copolymers.
• Purification: The resulting copolymer is purified to remove any unreacted monomers and other impurities using various purification techniques, such as filtration, washing and drying.
• Characterization: The final phase of the synthesis process is the characterization of the copolymer. This involves determining the molecular weight, composition and other properties of the copolymer.

It appears as a milky liquid with good compatibility with polar solvents such as alcohol and good compatibility and synergistic thickening properties with anionic and non-ionic surfactants for polar solvent systems.

What they are used for and where

Cosmetics

Viscosity-enhancing and emulsion-stabilising agents with film-forming and fixation properties, fast-thickening binders.

• Antistatic agent. Static electricity build-up has a direct influence on products and causes electrostatic adsorption. The antistatic ingredient reduces static build-up and surface resistivity on the surface of the skin and hair.
• Binder agent. Ingredient that is used in cosmetic, food and pharmaceutical products as an anti-caking agent with the function of making the product in which it is incorporated silky, compact and homogenous. The binder, either natural such as mucilage, gums and starches or chemical, may be in the form of a powder or liquid.
• Film-forming agent. It produces, upon application, a very thin continuous film with an optimal balance of cohesion, adhesion and stickiness on skin, hair or nails to counteract or limit damage from external phenomena such as chemicals, UV rays and pollution.

Use: 

• Viscosity enhancing agents, suspension or emulsion stabiliser 0.5%
• Binding, fixative, film-forming agents max. 25%

Safety

Health and Safety Considerations

Safety in Use
Acrylates Copolymer is generally considered safe for use in cosmetics and personal care products. It is well-tolerated by the skin and is not known to cause irritation or sensitization when used at approved concentrations. However, consumers with particularly sensitive skin should perform a patch test before use.

Allergic Reactions
Allergic reactions to Acrylates Copolymer are rare, but as with any chemical ingredient, individuals with sensitive skin or a history of allergies should exercise caution when using products containing this ingredient.

Toxicity and Carcinogenicity
It has been studied for safety and is considered safe for use in cosmetics when used within the recommended concentrations. International regulations set concentration limits to ensure consumer safety.

Environmental and Safety Considerations
Acrylates Copolymer is a synthetic polymer, raising environmental concerns regarding its biodegradability. Although it does not pose an immediate environmental hazard, its long-term accumulation in ecosystems, especially aquatic systems, can be problematic. It is recommended to dispose of products containing this ingredient responsibly to reduce environmental impact.

Regulatory Status
Acrylates Copolymer is approved for use in cosmetics and personal care products by regulatory bodies such as the European Union and the Food and Drug Administration (FDA) in the United States. It is regulated to ensure safe use within specific concentration limits in cosmetic formulations.

Studies

The presence of residual monomers could be toxic if 2-ethylhexyl acrylate exceeds a concentration of 21% on the skin, however the "Final Report on the Safety Evaluation of Acrylate Copolymer and 33 Related Cosmetic Ingredients" concluded that "Although monomers may be toxic, the levels that would be found in cosmetic formulations are not considered a safety hazard. Consequently, these acrylate copolymers are considered safe for use in cosmetic formulations when formulated to avoid irritation." (1).

Acrylates copolymer studies

• Molecular Formula  C₁₄H₂₂O₆
• Molecular Weight     286.32
• Exact Mass   286.32100
• CAS  25133-97-5
• UNII    
• EC Number   607-559-5
• DSSTox Substance ID  
• IUPAC  ethyl prop-2-enoate;methyl 2-methylprop-2-enoate;2-methylprop-2-enoic acid
• InChI=1S/2C5H8O2.C4H6O2/c1-4(2)5(6)7-3;1-3-5(6)7-4-2;1-3(2)4(5)6/h1H2,2-3H3;3H,1,4H2,2H3;1H2,2H3,(H,5,6)
• InChl Key      WRQSVSBTUKVOMY-UHFFFAOYSA-N
• SMILES   CCOC(=O)C=C.CC(=C)C(=O)O.CC(=C)C(=O)OC
• MDL number  
• PubChem Substance ID    

Synonyms

• 2-Propenoic acid, 2-methyl-, polymer with ethyl 2-propenoate and methyl 2-methyl-2-propenoate
• Methyl methacrylate, polymer with ethyl acrylate, methacrylic acid
• ethyl prop-2-enoate;methyl 2-methylprop-2-enoate;2-methylprop-2-enoic acid
• Methacrylic acid,ethyl acrylate,methyl methacrylate polymer
• Ethyl acrylate,methyl methacrylate,methacrylic acid polymer

References_________________________________________________________________________

(1) Zondlo Fiume M. Final report on the safety assessment of Acrylates Copolymer and 33 related cosmetic ingredients. Int J Toxicol. 2002;21 Suppl 3:1-50. doi: 10.1080/10915810290169800.

Abstract. Ingredients in the Acrylates Copolymer group all contain the monomers acrylic acid or methacrylic acid or one of their salts or esters. These ingredients are considered similar in that they are uniformly produced in chemical reactions that leave very little residual monomer. Although residual acrylic acid may be as high as 1500 ppm, typical levels are 10 to 1000 ppm. There is sufficient odor if residual monomers are present to cause producers to keep levels as low as possible. These ingredients function in cosmetics as binders, film formers, hair fixatives, suspending agents, viscosity-increasing agents, and emulsion stabilizers. Concentrations may be as high as 25% if used as a binder, film former, or fixative; or as low as 0.5% if used as a viscosity-increasing agent, suspending agent, or emulsion stabilizer. These very large polymers exhibit little toxicity. In rabbits and guinea pigs, Acrylates Copolymer did produce irritation, but no evidence of sensitization was found. The principle concern regarding the use of these polymer ingredients is the presence of toxic residual monomers. In particular, although 2-ethylhexyl acrylate was not genotoxic, it was carcinogenic when applied at a concentration of 21% to the skin of C3H mice. Lower concentrations (2.5%) and stop-dose studies at high concentrations (43%) were not carcinogenic. 2-Ethylhexyl acrylate was not carcinogenic in studies using NMRI mice. Whether an increase in carcinogenesis was seen or not, there was evidence of severe dermal irritation in these 2-ethylhexyl acrylate studies. Another concern regarding residual monomers was inhalation toxicity. Although the acrylic acid monomer is a nasal irritant, exposure to the monomer from use of these polymers in cosmetic formulations would always be less than the established occupational exposure limits for nasal irritation. Although there appears to be a huge variation in the mix of monomers used in the synthesis of these polymers, they are similar in that the polymers, except for dermal irritation, are not significantly toxic, and residual monomer levels are kept as low as possible. Although the monomers may be toxic, the levels that would be found in cosmetic formulations are not considered to present a safety risk. Accordingly, these Acrylate Copolymers are considered safe for use in cosmetic formulations when formulated to avoid irritation.

El-Sayed, S. M., Madani, M., & El-Bayoumi, A. S. (2009). Analytical calculations and properties of γ-rays polymerization of novel acrylates copolymer system. Physica B: Condensed Matter, 404(21), 4117-4124.

Abstract.  A detailed study of some physical properties of pure PMMA (polymethyl methacrylate) film and MMA/Ani (methyl methacrylate/aniline) films is presented. Films of thicknesses ranged from 0.04 to 0.72 mm for MMA/Ani were prepared while it is 0.68 mm for PMMA. The structure of the sample is analyzed by X-ray diffraction technique and is found to be amorphous (PMMA) and partially crystalline (MMA/Ani). Ultra violet–visible electronic absorption spectra measurements were analyzed to obtain some important parameters such as molar extrication coefficient, oscillator strength, dipole strength and having good thermal stability (Td >300 °C) was also reported. TGA studies revealed that the thermal stability of polymethyl methacrylate, prepared by radiation polymerization of methyl methacrylate, improved after copolymerization with aniline. Also, optical behavior of film samples was analyzed by obtaining transmission spectra, in the wavelength range of 200–1100 nm. It was found that all studied samples lead to the appearance of a second edge at lower photon energy due to the formation of the induced energy states. From the intensity of absorption interband transitions (B and Q) which are assigned as type π–π* for both PMMA and MMA/Ani films, the energy gaps Eg1 and Eg2 were calculated respectively. The optical conductivity (σ) was determined and it was found that with the increase of thicknesses optical energy gap decreases monotonically and the refractive index increases.

Lin, J., Zheng, C., Zhu, M. N., Chen, Y. Z., Lu, P. P., Liu, Q., ... & Xu, C. L. (2015). Comparison of copolymer emulsions of fluorine and siloxane‐containing acrylates with core–shell structure for water‐repellent cotton fabrics coatings. Polymers for Advanced Technologies, 26(1), 68-76.