Acrylate Monomers are a group of chemical compounds that serve as the building blocks for various polymers. They are widely used in the formulation of plastics, adhesives, coatings, and cosmetics due to their versatility and ability to form durable and flexible materials. In cosmetic applications, acrylate monomers are valued for their film-forming, thickening, and emulsifying properties, contributing to the stability and performance of beauty products.

Chemical Composition and Structure

Acrylate Monomers include various chemical structures, such as:

• Acrylic Acid: A basic monomer that can be polymerized to form polyacrylate.
• Methacrylate Monomers: Variants such as methyl methacrylate, which are often used to create more durable films.
• Alkyl Acrylates: Such as butyl acrylate, which enhance flexibility and adhesion properties.

These monomers possess a vinyl group (C=C) that enables polymerization, forming long chains that impart unique characteristics to the resulting materials.

Physical Properties

• Appearance: Typically clear, colorless liquids or solids, depending on the specific monomer.

• Solubility: Generally soluble in organic solvents; some may be soluble in water.

• pH: Neutral to slightly acidic, depending on the specific monomer.

• Odor: May have a faint acrid smell, depending on the specific compound.

• Stability: Generally stable under normal storage conditions; must be protected from light and moisture.

Production Process

1. Synthesis: Acrylate monomers are synthesized through various chemical reactions, often starting from acrylic acid or its derivatives.

2. Purification: The resulting monomers are purified to remove any impurities and by-products, ensuring high-quality products.

3. Formulation: Acrylate monomers can be mixed with other ingredients and polymerized in situ to create desired formulations.

Applications

• Cosmetics: Used in skin care products, hair care products, and makeup for their thickening and film-forming properties, which enhance product texture and stability.

• Adhesives: Serve as the primary component in pressure-sensitive adhesives due to their strong adhesion and flexibility.

• Coatings: Commonly used in paint and surface coatings to improve durability and gloss.

Environmental and Safety Considerations

Acrylate Monomers are generally regarded as safe for use in cosmetics when applied according to recommended guidelines. However, some individuals may experience sensitivities or allergic reactions (1).

Responsible sourcing and formulation practices are essential to ensure that these ingredients are free from harmful contaminants and produced sustainably.

References__________________________________________________________________________

(1) Chou M, Dhingra N, Strugar TL. Contact Sensitization to Allergens in Nail Cosmetics. Dermatitis. 2017 Jul/Aug;28(4):231-240. doi: 10.1097/DER.0000000000000301. PMID: 28719472.

Abstract. Ingredients found in the nail cosmetic industry, including but not limited to methacrylate and acrylate monomers, formaldehyde, and toluene sulfonamide-formaldehyde resin, can incite allergic contact dermatitis. An eczematous outbreak presents on areas surrounding the nail plate and may spread through contact transfer of the allergen, commonly to the face and neck. Even components that were originally deemed nonsensitizing, such as the ubiquitous cyanoacrylate adhesive family, have been found to be allergenic. They do not, however, cross-react with methacrylates and acrylates. Alternative options for individuals with allergic contact dermatitis reactions to these ingredients can be avoidance of these procedures or use of products that are "3, 4, 5 free" in which the common allergens dibutyl phthalate, toluene, and formaldehyde are absent. In cases where strengthening of the nail is the sole purpose, nail wraps or preformed nails can be applied for non-cyanoacrylate-sensitive individuals.

Sasseville D. Acrylates in contact dermatitis. Dermatitis. 2012 Jan-Feb;23(1):6-16. doi: 10.1097/DER.0b013e31823d1b81. PMID: 22653063.

Abstract. Acrylates are plastic materials that are formed by the polymerization of monomers derived from acrylic or methacrylic acid. They have found numerous applications in paints, varnishes and adhesives, in the printing industry, in the medical and dental professions, and in artificial nails. Beginning in the 1950s, many reports of occupational and nonoccupational allergic contact dermatitis to (meth)acrylate monomers have been published. These molecules are strong irritants, and patch testing can induce active sensitization. When patch tested, acrylate-allergic patients often display multiple positive tests. These reactions may represent cross-reactions, or concomitant reactions due to the presence, in the products responsible for sensitization, of impurities not disclosed in material safety data sheets. (Meth)acrylates are volatile and unstable chemicals, as demonstrated by their rapid disappearance from commercially available patch test allergens when exposed to air for more than a few hours.

_________________

Alizadehgharib S, Östberg AK, Dahlgren U. Effects of the methacrylate/acrylate monomers HEMA, TEGDMA, DEGDA, and EMA on the immune system. Clin Exp Dent Res. 2017 Nov 17;3(6):227-234. doi: 10.1002/cre2.93. 

Abstract. Incomplete curing of dental fillings may lead to leakage of methacrylate/acrylate monomers, which may come in contact with different cells of the immune system in oral tissues. Very little is known about the different immunologic effects caused by these methacrylates/acrylates. The objective of the present study was to study if and how the methacrylate/acrylate monomers ethyl methacrylate (EMA) and diethylene glycol diacrylate (DEGDA) affect the immune system in vivo and in vitro in comparison to 2-hydroxyethyl methacrylate (HEMA) and triethylene glycol dimethacrylate (TEGDMA). Human peripheral blood mononuclear cells were exposed to the different monomers (500 and 1000 μM) for 24 hr in vitro. BioPlex Pro™ assays were used for cytokine analysis. In vivo, BALB/c mice were immunized subcutaneously at the base of the tail with HEMA, TEGDMA, EMA, or DEGDA in combination with ovalbumin (OVA) in order to study adjuvant properties of the 4 monomers. Peripheral blood mononuclear cells exposed to DEGDA had viability less than 50% of the cells. A pattern was observed where the levels of most cytokines were elevated after exposure to HEMA or TEGDMA. Since that, many cells died after DEGDA-exposure, the only observed cytokine secretion was a significantly increased production of interleukin-18. In the in vivo experiments, all mice immunized with DEGDA died after the booster injection. Mice receiving OVA in combination with HEMA, TEGDMA, or EMA developed a higher immunoglobulin G anti-OVA antibody levels compared to the group immunized with OVA alone. We could not demonstrate any significant difference in antibody levels among the mice receiving the various methacrylate/acrylate monomers. The different monomers affected the production, increase and decrease, of different cytokines in vitro but resulted also in vivo in increased antibody production and T-cell activity.

Koschitzki F, Wanka R, Sobota L, Gardner H, Hunsucker KZ, Swain GW, Rosenhahn A. Amphiphilic Zwitterionic Acrylate/Methacrylate Copolymers for Marine Fouling-Release Coatings. Langmuir. 2021 May 11;37(18):5591-5600. doi: 10.1021/acs.langmuir.1c00428. 

Abstract. Methacrylate and acrylate monomers are popular building blocks for antifouling (AF) and fouling-release (FR) coatings to counteract marine biofouling. They are used in various combinations and often combined into amphiphilic materials. This study investigated the FR properties of amphiphilic ethylene glycol dicyclopentenyl ether acrylate (DCPEA) and the corresponding methacrylate (DCPEMA) blended with 5 wt % zwitterionic carboxybetaine acrylate (CBA) and the corresponding methacrylate (CBMA). A series of (co)polymers with different acrylate/methacrylate compositions were synthesized and tested against the attachment of the diatom Navicula perminuta and in short-term dynamic field exposure experiments. The more hydrophobic methacrylate DCPEMA homopolymer outperformed its acrylate counterpart DCPEA. Incorporated zwitterionic functionality of both CBMA and CBA imparted ultralow fouling capability in the amphiphilic polymers toward diatom attachment, whereas in the real ocean environment, only the employment of CBMA reduced marine biofouling. Moreover, it was observed that CBA-containing coatings showed different surface morphologies and roughnesses compared to the CBMA analogues. Particularly, a high impact was found when acrylic CBA was mixed with methacrylic DCPEMA. While the wettability of the coatings was comparable, investigated methacrylates in general exhibited superior fouling resistance compared to the acrylates.