MMA
Methyl methacrylate
- CAS
- Formula
- C₅H₈O₂
- Polymer Tg
- ~105 °C
Used forMMA floor and deck systems; hard segment in acrylic resins.
Strong odor and highly flammable (flash point about 10 °C). Ventilate and remove ignition sources.
Full profileAcrylic and methacrylic monomers polymerize through their carbon–carbon double bonds into tough, clear, weather-resistant binders. They build latex paints, fast-curing MMA floors and the acrylic polyols in premium urethane topcoats.
Acrylic monomers are esters of acrylic or methacrylic acid, each carrying a reactive carbon–carbon double bond. Unlike isocyanates or epoxies, they do not cure by two different resins meeting. Instead, a free radical opens the double bond and adds monomer after monomer into a long chain.
Coatings use acrylics in three main ways. Waterborne latex binders are polymerized at the factory; on the wall, the film forms as water evaporates and particles fuse together. MMA (methyl methacrylate) floor systems polymerize on the floor itself when a peroxide initiator is added, curing in about an hour even near freezing. Acrylic polyols carry hydroxyl groups from HEMA and are crosslinked with aliphatic isocyanates for durable, high-gloss topcoats.
Formulators tune hardness by blending hard monomers (MMA, styrene) with soft monomers (butyl acrylate, 2-EHA), targeting a glass transition temperature that suits the climate and use.
The building blocks of acrylic latex, MMA floors and acrylic polyols.
Used forMMA floor and deck systems; hard segment in acrylic resins.
Strong odor and highly flammable (flash point about 10 °C). Ventilate and remove ignition sources.
Full profileUsed forFlexibility in latex paints, elastomeric roof coatings and adhesives.
Paired with MMA or styrene to dial in film hardness.
Full profileUsed forElastomeric coatings, sealants and pressure-sensitive adhesives.
Very soft and water-resistant; common in roof coatings and caulks.
Full profileUsed forStyrene-acrylic latexes, unsaturated polyester and vinyl ester resins.
A cheaper hard monomer than MMA, but yellows and chalks more outdoors.
Full profileUsed forPuts hydroxyl groups on acrylic polyols for 2K urethane cure.
A known skin sensitizer, which is why uncured acrylates demand glove discipline.
Full profileUsed forSmall doses improve latex stability, adhesion and pigment wetting.
Corrosive as a raw monomer; most latexes use only a few percent.
Full profileUsed forHelps latex particles fuse into a continuous film.
The Texanol™-type coalescent: lowers minimum film-forming temperature so latex paints cure in cool weather.
Full profileUsed forStarts the free-radical cure of MMA floors and polyester/vinyl ester resins.
An organic peroxide: store cool and never mix it directly with amine accelerators.
Full profileFree-radical polymerization runs in three steps. Initiation: a peroxide such as benzoyl peroxide splits into radicals, often helped by an amine accelerator. Propagation: each radical opens a monomer’s C=C bond, creating a new radical at the chain end that grabs the next monomer. Termination: two radicals meet and the chain stops growing.
Oxygen scavenges radicals, so the surface of a curing MMA floor can stay tacky unless the resin contains a paraffin wax or is topcoated. Cure speed depends on initiator dose and temperature, which is why MMA systems are adjusted for cold rooms.
In latex paints the chemistry happens in the reactor. On the wall, film formation is physical: water leaves, particles pack together and coalesce. A coalescent such as TMPD-MIB temporarily softens the particles so they fuse in cool weather.
CH₂=C(CH₃)CO₂CH₃Methyl methacrylateBPO → R•Peroxide radicals–[CH₂–C(CH₃)(CO₂CH₃)]ₙ–PMMAOne radical can add thousands of monomers before the chain terminates.
Approximate homopolymer glass transition temperatures. Blending monomers sets the final film’s hardness and flexibility.
| Monomer | Polymer Tg | Character | Typical role |
|---|---|---|---|
| MMA | ~105 °C | Hard, clear, weatherable | MMA floors, hard segment |
| Styrene | ~100 °C | Hard, economical, yellows outdoors | Styrene-acrylic latex |
| n-Butyl acrylate | ~−54 °C | Soft, flexible | Latex paints, elastomerics |
| 2-Ethylhexyl acrylate | ~−50 to −65 °C | Very soft, water-resistant | Roof coatings, sealants, adhesives |
| HEMA | — | Hydroxyl-functional | Acrylic polyols for 2K urethanes |
Liquid acrylic monomers are volatile, flammable and often skin sensitizers. Cured acrylic films are generally inert, but the raw materials demand care.
Always follow the product’s Safety Data Sheet, your employer’s safety program and local regulations. This page is general reference information, not a substitute for them.
MMA cures by free-radical polymerization, which keeps running at low temperatures when the initiator dose is adjusted. Many systems are rated for cold-room installation and return to service in about an hour.
Single-component acrylics dry by solvent or water evaporation and are economical. 2K acrylic-urethanes crosslink an acrylic polyol with an aliphatic isocyanate for much better chemical and abrasion resistance.
Glass transition temperature is where a polymer shifts from hard and glassy to soft and rubbery. Blending high-Tg and low-Tg monomers sets how hard, flexible and dirt-resistant a film is.
It temporarily softens latex particles so they fuse into a continuous film as water evaporates, especially in cool weather, then slowly leaves the film.