Polymethyl methacrylate has good comprehensive mechanical properties and is in the forefront of general-purpose plastics. The tensile, bending and compression strengths are higher than those of polyolefins, and also higher than that of polystyrene and polyvinyl chloride. Poor, but also slightly better than polystyrene. The cast bulk polymethyl methacrylate sheet (such as aerospace plexiglass sheet) has higher mechanical properties such as stretching, bending and compression, and can reach the level of engineering plastics such as polyamide and polycarbonate.
Polymethyl methacrylate has less electrical properties than non-polar plastics such as polyolefins and polystyrene due to the polar methyl ester group at the side of the main chain. The polarity of the methyl ester group is not too large, and the polymethyl methacrylate still has good dielectric and electrical insulating properties. It is worth noting that polymethyl methacrylate and even the entire acrylic plastic have excellent arc resistance. Under the action of arc, the surface does not produce carbonized conductive paths and arc track phenomena. 20 ° C is a secondary transition temperature, corresponding to the temperature at which the side methyl ester group begins to move, below 20 ° C, the side methyl ester group is in a frozen state, and the electrical properties of the material are increased above 20 ° C.