Styrofoam?
Usually we call it Styrofoam, however it's actually one of the most common form of Polystyrene. Introduced in 1954 styrofoam is a trade name, the actual or real name of the material is foamed polystyrene. Ray Mclntire was the one to invent Styrofoam however he claimed it was accidental he was at first trying to create a flexible electrical insulator. Mclntire tried to create something like a rubber aiming to be similar to polymer, he did so through mixing styrene with isobutylene. The end result was the invention of foam polystyrene which was 30 times lighter than the original material.