Synthetic rubber, production

Data for. synthetic rubber production exclude production from the one-time USSR, Central Europe and Socialist Countries of Asia. 

When polymerizing dienes for synthetic rubber production, coordination catalysts are used to direct the reaction to yield predominantly 1,4-addition polymers. Chapter 11 discusses addition polymerization. The following reviews some of the physical and chemical properties of butadiene and isoprene. 

Butadiene is by far the most important monomer for synthetic rubber production. It can be polymerized to polybutadiene or copolymerized with styrene to styrene-butadiene rubber (SBR). Butadiene is an important intermediate for the synthesis of many chemicals such as hexa-methylenediamine and adipic acid. Both are monomers for producing nylon. Chloroprene is another butadiene derivative for the synthesis of neoprene rubber. 

Isoprene is the second important conjugated diene for synthetic rubber production. The main source for isoprene is the dehydrogenation of C5 olefins (tertiary amylenes) obtained by the extraction of a C5 fraction from catalytic cracking units. It can also be produced through several synthetic routes using reactive chemicals such as isobutene, formaldehyde, and propene (Chapter 3). 

Paramount among the outlets for petroleum raw materials outside the field of fuels and lubricants are the elastomers and plastics. It is expected that synthetic rubber production in 1951 will exceed 800,000 long tons (1.8 billion pounds) while, during the same period, nearly two billion pounds of plastics also will be produced. It has been demonstrated to the American consumer that synthetic rubber is equal or superior to the natural product for many applications, and plastic products such as nylon fabrics, polyvinyl chloride upholstery, and polystyrene toys and gadgets are now considered a part of our way of life. 

These sizable outlets for petroleum products are of relatively recent development. Only a decade ago synthetic rubber production was under 20,000,000 pounds per year. Twenty-five years ago synthetic rubber was virtually unknown in America, and total production of synthetic plastics, chiefly phenolics from coal tar, was only 12,000,000 pounds per year. Chemicals and chemical intermediates were produced from coal, minerals, and vegetable products, but the petroleum industry was devoting its interest almost exclusively to the production of fuels and lubricants. 

The two primary hydroxyl groups provide fast reaction rates with diisocyanates, which makes this diol attractive for use as a curative in foams. It provides latitude in improving physical properties of the foam, in particular the load-bearing properties. Generally, the ability to carry a load increases with the amount of 1,4-cydohexanedimethanol used in producing the high resilience foam (95). Other polyurethane derivatives of 1,4-cyclohexanedimethanol indude elastomers useful for synthetic rubber products with a wide range of hardness and elasticity (96). 

Of special interest for petrochemical and organic synthesis is the implementation of thermodynamically hindered reactions, among which incomplete benzene hydrogenation or incomplete cyclohexene and cyclohexadiene dehydrogenation should be mentioned. Cost-effective methods of cyclohexene production would stimulate the creation of new processes of phenol, cyclohexanol, cyclohexene oxide, pyrocatechol synthesis, cyclohexadiene application in synthetic rubber production, and a possibility for designing caprolactam synthesis from cyclohexene and cyclohexadiene via combined epoxidation. At present, the most... 

Zachoval, J. and Brajko, V., Synthetic Rubbers Production Methods , in Elastomers and Rubber Compounding Materials, Elsevier Science, Amsterdam, 1989, pp. 65-75. 

The indene-derived group. At the Velsicol Chemical Corporation in Chicago in 19 3, Dr. Julius Hyman was seeking new uses for the cyclopentadiene which was a by-product of U.S. synthetic rubber production and was already used by Velsicol for the manufacture of resins and varnishes by the Diels-Alder reaction (6). A literature search revealed Straus s 1930 synthesis of hexachlorocyclopentadiene ( hex ) and, since chlorinated dienes are frequently rather inert, Hyman was interested to determine if hex would participate in the Diels-Alder reaction, either with itself or with cyclopentadiene. 

Alkenes that easily form carbocations are good candidates for cationic polymerization, which is just another example of electrophilic addition to an alkene. Consider what happens when pure isobutylene is treated with a trace of concentrated sulfuric acid. Protonation of the alkene forms a carbocation. If a large concentration of isobutylene is available, another molecule of the alkene may act as the nucleophile and attack the carbocation to form the dimer (two monomers joined together) and give another carbocation. If the conditions are right, the growing cationic end of the chain will keep adding across more molecules of the monomer. The polymer of isobutylene is polyisobutylene, one of the constituents of butyl rubber used in inner tubes and other synthetic rubber products. 

Activator and plasticizer for general use in natural and synthetic rubber products. 

Department of Commerce, Rubber—Annual Report by the Secretary of Commerce, annual, 1948-. Monthly and annual data on natural and synthetic rubber production, consumption, supply, and stocks. Also data on manufacture of tires. 

This is the most important general purpose of synthetic rubber and represents more than half of all synthetic rubber production. It is a copolymer of 1,3-butadiene and styrene, and is a descendent of the original Bunas first produced in Germany during the 1930s [2]. 

In the curing of natural and synthetic rubber products, increasing the rate at which the product reaches its final chemical state ... 

In 1943 Houdry Process Corp. announced the Houdry adiabatic process for catalytic cracking which eliminated the molten salt heat transfer system. This process did not go commercial for catalytic cracking, but it was successfully used for butane dehydrogenation to produce butenes for synthetic rubber production during World War II. 

Details A liquid, a crosslinking agent and a monomer for synthetic rubber production. 

V. Garmonov Analysis of Products Synthetic Rubbers Production, Khimiya, Moscow (1964) (in Russian). 

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