Polyurethane
A polyurethane is any polymer consisting of a chain of organic units joined by urethane links. It can be made in a variety of textures and hardnesses by varying the particular monomers used and adding other substances. It is used in adhesives, elastomers, foams, sealss, gaskets, condoms, carpet underlayment, and hard parts. Carbon dioxide is released during the polymerisation, creating bubbles in the liquid, which then hardens to form a solid foam.