Polymethylacrylate

Polymethylacrylate is the polymer obtained by polymerizing the methyl acrylate monomer, CH2=CHCOOCH3. The repeating unit is −[CH2−CH(COOCH3)]−. It is a member of the polyacrylate family and is distinct from polymethyl methacrylate (PMMA), which is formed from methyl methacrylate.

Synthesis and processing: PMA is produced by radical addition polymerization using initiators such as azobisisobutyronitrile (AIBN) or peroxide catalysts. Polymerization can be conducted in bulk, solution, suspension, or emulsion to give a range of molecular weights. The polymer can be fabricated into films, sheets, coatings, or molded parts, and can be used in latex form for paints and coatings. Copolymerization with other monomers allows tailoring of properties such as hardness, flexibility, and solvent resistance.

Properties and applications: Polymethylacrylate is a clear, colorless thermoplastic with general chemical resistance to many common solvents and good optical clarity. Its mechanical properties and glass transition temperature depend on molecular weight and comonomers, and it can be processed by standard thermoplastic methods such as extrusion and molding. Applications include coatings, adhesives, sealants, protective films, and packaging materials; it is sometimes used where a more flexible or cost-effective alternative to PMMA is desired.

Safety and environmental notes: Methyl acrylate monomer is volatile and can be an irritant; handling requires appropriate controls. The polymer itself is typically inert under normal conditions and can be recycled or disposed of with standard plastic waste streams depending on formulation and additives.