Polyisocyanates became commercially available in 1952, and production of flexible polyurethane foam began in 1954 by combining toluene diisocyanate (TDI) and polyester polyols. Early work focused on the production of fibers and flexible foams and PUs were applied on a limited scale as aircraft coating during World War II. The new polymers had some advantages over existing plastics that were made by polymerizing olefins or by polycondensation, and were not covered by patents obtained by Wallace Carothers on polyesters. Otto Bayer and his coworkers at IG Farben in Leverkusen, Germany, first made polyurethanes in 1937. History Otto Bayer in 1952 demonstrating his creation Global production in 2019 was 25 million metric tonnes, accounting for about 6% of all polymers produced in that year. Both the isocyanates and polyols used to make a polyurethane contain two or more functional groups per molecule. Since a polyurethane contains two types of monomers, which polymerize one after the other, they are classed as alternating copolymers. Ī polyurethane is typically produced by reacting an isocyanate with a polyol. Foams are the largest application accounting for 67% of all polyurethane produced in 2016. These include rigid and flexible foams, and coatings, adhesives, electrical potting compounds, and fibers such as spandex and polyurethane laminate (PUL). This chemical variety produces polyurethanes with different chemical structures leading to many different applications. In contrast to other common polymers such as polyethylene and polystyrene, polyurethane is produced from a wide range of starting materials. Polyurethane ( / ˌ p ɒ l i ˈ jʊər ə ˌ θ eɪ n, - j ʊəˈr ɛ θ eɪ n/ often abbreviated PUR and PU) refers to a class of polymers composed of organic units joined by carbamate (urethane) links. Polymer composed of a chain of organic units joined by carbamate (urethane) links Polyurethane synthesis, wherein the urethane groups −NH−(C=O)−O− link the molecular units A kitchen sponge made of polyurethane foam
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