The full name of polyurethane is polyurethane, which is a general term for macromolecular compounds with repeating carbamate groups (NHCOO) on the main chain. It is formed by addition polymerization of organic diisocyanate or polyisocyanate and dihydroxy or polyhydroxy compound. In addition to carbamate, polyurethane macromolecules can also contain ether, ester, urea, biuret, allophanate and other groups. According to the different raw materials used, there are products with different properties, generally two types of polyester type and polyether type. It can be used to make plastics, rubbers, fibers, rigid and flexible foams, adhesives and coatings.