Germany polyurethane production

The Eastern European countries include USSR, East Germany, Poland, Hungary, Bulgaria, Rumania, Czechoslovakia, and Albania. These countries consist of about 400 million inhabitants. These socialistic countries have state-controlled economies that only recently are beginning to swing towards the manufacture of consumer items. The USSR is probably the largest volume consumer of polyurethane products, followed closely by East Germany. 

Bayer AG s Bayer Material Science division (Leverkusen, Germany www.bayer.com) is building a 230 000 tpa plant in Caojing, to produce diphenyl methane diisocyanate, a raw material for polyurethane production. The plant is due on line by 2008. 

The telomeric aliphatic polyesters were produced by polycondensation based on adipic acid and hexamethylene glycol in various stoichiometric amounts to generate polyesters of different end group functionality. The polyesters of different molar mass and corresponding reference samples were synthesized at the Center for Macromolecular Chemistry, Berlin, Germany. These types of polyesters are widely used as lacquers and precursors for the production of several important polyurethanes. 

In spite of the current dominance of applications for aniline in the production of polyurethanes and chemicals for rubber processing, aniline has remained an important raw material for the dyestuffs industry. It is used today for production of the dyes Solvent Red 19 and Solvent Red 23, which are used in West Germany and France as markers for heating oil, to distinguish it from diesel oil methyl-naphthalene is used as a solvent for the dyes. 

In 1937, in Germany, IG Farben started the development of polyurethane (PU) and in 1947 Bayer published an impressive account of the synthesis of PU and polyureas from diisocyanates and dihidroxy or diamino compounds, respectively. Later on in 1961 the PU were found to be useful for the production of plastics, foams, adhesives, fibres and corrosion resistant coatings [13]. 

Polyurethanes were first discovered by Otto Bayer and coworkers at I. G. Farbenindustrie, Germany, in the late 1930s. The first products were obtained by reacting an aliphatic diisocyanate with an aliphatic diamine or diol. These materials soon found commercial uses and were marketed under the trade names of Irgamid U, for plastics, and Perlon U for synthetic fibers and bristles. Very soon after this, it was discovered that isocyanates could be used to bond rubber to metal, which in turn led to the development of urethane adhesives based on polyester diols these adhesives were commercialized under the trade name Polystal. For a more complete account of the history of polyurethanes, see refs. 2, 4, and 5. 

The initial step to prepare polyurethane polymers for solution wet or dry spinning includes reaction of 1000-3500 molecular weight macroglycol with a diisocyanate at molar ratios of between about 1 1.4 and 1 2.0. Reaction conditions must be carefully selected and controlled to minimize side reactions, eg, allophanate and biuret formation, which can result in trifunctional branched chains and ultimately to insoluble cross-linked poljuners. For the prepolymer reaction, poly(tetramethylene ether) glycol [25190-06-1] and bis(4-isocyanatophenyl) methane [101-68-8] are currently the most commonly used macroglycol and diisocyanate. Several types of polyester-based macroglycols are included in spandex producers product lines, but with the exception of Dorlastan, made by Bayer AG in Germany, the polyester-based products represent only a minor part of their spandex fiber production. 

Polyurethanes (PUs) are a family of condensation polymers that include the urethane (-NHCOO-) group in the chemical structure (Figure 5.1). The history of PUs started in 1937 when Dr Otto Bayer of Bayer Germany invented the diisocyanate polyaddition process. The early applications of PUs were mainly on soft foams and nonsegmented semicrystalline fibers. The lack of rubber materials during WWII has led to the intensive development of PU elastomers. In 1950, Bayer launched the first PU elastomer product, Vulkollan rubbers. Since then, PU elastomers have been used extensively, particular in medical, textile, automobile, and architecture industries [1-3]. 

A pilot plant was opened in the UK by ICI in 1998 to look at the feasibility of chemically recycling polyurethane, their method being a process called split-phase glycolysis [8]. Like hydrolysis, the method is complicated by the presence of by-products. Commercial depolymerisation units using the glycolysis of polyurethanes operate in Germany, Austria and Denmark [4]. The requirement for separation can be avoided in this case by further chemical reactions. The basic chemistry involved in these reactions is presented by Ehrig [9] for those who require further details. 

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