Poly(methyl Methacrylate)

Poly(methyl methacrylate) (PMMA) is a transparent thermoplastic, often used as a lightweight or shatter-resistant alternative to glass. It is sometimes called acrylic glass. Chemically, it is the synthetic polymer of methyl methacrylate. The material was developed in 1928 in various laboratories, and was first brought to market in 1933 by the Rohm and Haas Company, under the trademark Plexiglas. It has since been sold under many different names, including Lucite and Perspex.

The often-seen spelling poly(methyl 2-methylpropanoate) with -an- is an error for poly(methyl 2-methylpropenoate), based on propenoic acid.

PMMA is an economical alternative to polycarbonate (PC) when extreme strength is not necessary. Additionally, PMMA does not contain the potentially harmful bisphenol-A subunits found in polycarbonate. It is often preferred because of its moderate properties, easy handling and processing, and low cost. The non-modified PMMA behaves in a brittle manner when loaded, especially under an impact force, and is more prone to scratching than conventional inorganic glass. However, the modified PMMA achieves very high scratch and impact resistance.