Plexiglas is a plastic polymer. Plexiglass will snap in two when bent or hit sharply. I love to use Lexan. You can almost bend it in half and it wont break. I use it whenever I need to recreate playfield plastics for pinball machine. If it can withstand a impact from a steel pinball flying at over 50 MPH it's gotta be strong. You can buy it most everywhere.

I found this on the web: Lexan Polycarbonate Sheet is one of the most widely known "plastics". Lexan Polycarbonate sheet with its unique combination of high impact strength, flame retardancy, and thermoformability makes it ideally suited for security applications. No other plastic can match Lexan's combination of light transmittance (clarity), and the ability to withstand extreme impact.