Polymethyl Methacrylate (PMMA) is a chemical compound, a transparent plastic polymer also known as acrylic or plexiglass.

The name describes the structure of the molecule:

• Poly indicates that the chemical structure is a polymer, meaning it is composed of many repeated molecular units, linked together in long chains.
• methyl refers to a methyl group, a functional group consisting of one carbon atom bonded to three hydrogen atoms.
• Methacrylate comes from methacrylic acid, an organic compound used as a base to produce polymers through polymerization reactions.

Chemical Industrial Synthesis Process

• Polymerization. The synthesis of PMMA begins with the polymerization of methyl methacrylate (MMA). This process can occur in solution, suspension, or bulk, depending on the desired properties of the final polymer.
• Control of characteristics. During polymerization, initiators, catalysts, and stabilizers can be added to control the molecular weight and physical properties of PMMA.
• Addition of dyes and additives. To achieve specific shapes and colors, dyes and other additives can be mixed with MMA before or during polymerization. This step is crucial to ensure uniform color distribution and precise shape realization.
• Forming. Once polymerization is complete, PMMA can be extruded, cast, or molded to form sheets, beads, fibers, or other configurations.
• Purification and finishing. The product can then be further processed, cut, or polished to achieve smooth, transparent surfaces or to finalize the desired shapes.
• Quality control. Each batch of PMMA undergoes rigorous quality testing to ensure transparency, weather resistance, and mechanical properties meet the required specifications.

What it is used for and where

In cosmetics, PMMA is used as a light-diffusing agent and filler in powders and other makeup products for its ability to provide a smooth, even finish. PMMA is often employed to create a "soft-focus" effect that minimizes the appearance of wrinkles and skin imperfections. It is valued for its transparency and durability, making it suitable also for use in skincare products as film-forming agents.

Cosmetics - INCI Functions

• 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.

CAS  9011-14-7

Main uses and benefits of polymethyl methacrylate.

Medical. Bone cements, contact and intraocular lens, screw fixation in bone, filler for bone cavities and skull defects, vertebrae stabilization in osteoporotic patients (1). 

Texture Enhancement. PMMA is used to improve the feel and consistency of cosmetic products, making them smoother and easier to apply.

Mattifying Effect. It provides a matte and uniform finish, ideal for makeup products like foundations and primers, where smooth coverage and a natural look are desired.

Film-forming Properties. It creates a thin film on the skin that can help protect and isolate the skin, enhancing the longevity of applied cosmetic products.

Shine Control. It helps control skin shine, reducing the glossy appearance and improving the overall aesthetic look of makeup.

Uniform Pigment Distribution. It helps to evenly distribute pigments in a formula, ensuring consistent and uniform color.

Stability and Durability. It contributes to the stability of cosmetic formulations and can increase the durability of the final product, holding up better over time.

References_____________________________________________________________________

(1) Frazer RQ, Byron RT, Osborne PB, West KP. PMMA: an essential material in medicine and dentistry. J Long Term Eff Med Implants. 2005;15(6):629-39. doi: 10.1615/jlongtermeffmedimplants.v15.i6.60. PMID: 16393131.

Abstract. The first use of polymethyl methacrylate (PMMA) as a dental device was for the fabrication of complete denture bases. Its qualities of biocompatibility, reliability, relative ease of manipulation, and low toxicity were soon seized upon and incorporated by many different medical specialties. PMMA has been used for (a) bone cements; (b) contact and intraocular lens; (c) screw fixation in bone; (d) filler for bone cavities and skull defects; and (e) vertebrae stabilization in osteoporotic patients. The many uses of PMMA in the field of medicine will be the focus of this review, with particular attention paid to assessing its physical properties, advantages, disadvantages, and complications. Although numerous new alloplastic materials show promise, the versatility and reliability of PMMA cause it to remain a popular and frequently used material.

Bettencourt, A., & Almeida, A. J. (2012). Poly (methyl methacrylate) particulate carriers in drug delivery. Journal of microencapsulation, 29(4), 353-367.

Abstract. Poly(methyl methacrylate) (PMMA) is one of the most widely explored biomedical materials because of its biocompatibility, and recent publications have shown an increasing interest in its applications as a drug carrier. PMMA-based particulate carriers (PMMAP) can be prepared either by polymerization methods or from pre-formed polymer-based techniques. Potential biomedical application of these particles includes their use as adjuvant for vaccines and carrier of many drugs as antibiotics and antioxidants via different routes of administration. Release of drugs from PMMAP occurs typically in a biphasic way with an incomplete drug release. To improve release profiles, recent strategies are focusing on increasing polymer hydrophilicity by synthesizing functionalized PMMA microspheres or by formulating PMMA composites with hydrophilic polymers. This review examines the current status of preparation techniques, drug release kinetics, biomedical applications and toxicity of these nano/micro PMMA-based particulate carriers.