Methyl methacrylate
The monomer behind fast-curing MMA floor systems and the hard segment of countless acrylic resins.
Methyl methacrylate is the methyl ester of methacrylic acid (molecular weight 100.12 g/mol). It is a clear, volatile liquid with a strong, characteristic odor and a flash point around 10 °C. Its homopolymer is PMMA, known as acrylic glass, with a Tg near 105 °C.
In coatings, MMA appears in two main ways:
MMA polymerizes by free radicals through its C=C double bond. On-site MMA systems cure in about an hour and keep curing at low temperatures, making them popular in cold storage and food plants. Oxygen inhibits cure at the surface, so formulations include wax or are topcoated.
MMA is highly flammable and its vapor is heavier than air. It irritates skin and the respiratory tract and can cause skin sensitization. Ventilate thoroughly, eliminate ignition sources, and manage odor in occupied buildings.
Uncured MMA monomer is volatile with a low odor threshold. The smell fades once the floor cures, but ventilation is essential during application.
Many MMA systems are designed for low-temperature installation, with initiator levels adjusted for the temperature. Follow the manufacturer’s cold-weather guidance.
