Otto Bayer and the History of Polyurethane

Polyurethane is an organic polymer  composed of  organic  units joined by  carbamate (urethane) links. While most polyurethanes are  thermosetting polymers  that do not melt when heated,  thermoplastic polyurethanes  are also available. According to the Alliance of The Polyurethane Industry,  Polyurethanes are formed by reacting a polyol (an alcohol with more than two reactive hydroxyl groups per molecule) with a diisocyanate or a polymeric isocyanate in the presence of suitable catalysts and additives. Polyurethanes are best known to the public in the form of flexible foams: upholstery, mattresses,  earplugs, chemical-resistant coatings, specialty adhesives and  sealants, and packaging. It also comes to the rigid forms of insulation for buildings, water heaters, refrigerated transport, and commercial and residential refrigeration. Polyurethane products often are simply called â€Å"urethanes†, but should not be confused with  ethyl carbamate, which is also called urethane. Polyurethanes neither contain nor are produced from ethyl carbamate. Otto Bayer Otto Bayer and co-workers at IG Farben  in Leverkusen, Germany,  discovered and patented the chemistry of polyurethanes in 1937.  Bayer (1902 - 1982) developed the novel polyisocyanate-polyaddition process. The basic idea which he documents from March 26, 1937, relates to spinnable products made of hexane-1,6-diisocyanate (HDI) and hexa-1,6-diamine (HDA). Publication of German Patent DRP 728981 on November 13, 1937: A process for the production of polyurethanes and polyureas. The team of inventors consisted of  Otto Bayer, Werner Siefken, Heinrich Rinke, L. Orthner and H. Schild. Heinrich Rinke   Octamethylene diisocyanate and butanediol-1,4 are the units of a polymer produced by Heinrich Rinke. He called this area of polymers polyurethanes, a name which was soon to become known worldwide for an extremely versatile class of materials.   Right from the start, trade names were given to polyurethane products. Igamid ® for plastics materials, Perlon ® for fibers.   William Hanford  and  Donald Holmes   William Edward Hanford and Donald Fletcher Holmes invented a process for making the multipurpose material polyurethane. Other Uses In 1969, Bayer exhibited an all-plastic car in  Dà ¼sseldorf, Germany. Parts of this car, including the body panels, were made using a new process called  reaction injection molding  (RIM), in which the reactants were mixed and then injected into a mold. The addition of fillers produced reinforced RIM (RRIM), which provided improvements in  flexural modulus  (stiffness), reduction in coefficient of thermal expansion  and better thermal stability. By using this technology, the first plastic-body automobile was introduced in the United States in 1983. It was called the  Pontiac Fiero. Further increases in stiffness were obtained by incorporating pre-placed glass mats into the RIM mold cavity, called resin injection molding, or structural RIM. Polyurethane foam (including foam rubber) is sometimes made using small amounts of  blowing agents  to give less dense foam, better cushioning/energy absorption or thermal insulation. In the early 1990s, because of their impact on  ozone depletion, the  Montreal Protocol  restricted the use of many  chlorine-containing blowing agents. By the late 1990s, blowing agents such as  carbon dioxide and pentane were widely used in North America and the EU.