Methacrylates (CH2=CMeCOO-) are the salts or esters of methacrylic acid.
Methacrylates contain methyl-vinyl groups, that is, two carbon atoms double bonded to each other, directly attached to the carbonyl carbon, and wherein the vinyl group is substituted with a non-terminal methyl group.
Methacrylates are common monomers in polymer plastics, forming the acrylate polymers. Methacrylates easily form polymers because the double bonds are very reactive. They are used as the monomer resin in some windscreen repair kits, and as bone cement for fixing prosthetic devices in orthopaedic surgery.