HOW Copolymer synthetic rubber is of the Buna S type, made principally from butadiene and styrene. 1 and 2. Styrene, a liquid, is a derivative of coal and one of the hydrocarbon family, but of a different molecular structure than butadiene. 3 and 4. Butadiene is a gas composed of hydro sen and carbon, the same as coal, oil, gasoline, turpentine, and
BUNA S G O V E R N M E N T S Y N T H E T I C benzene. It is piped in from the adjacent oil refinery. 5 . Here butadiene and styrene are mixed—three parts of butadiene to one part of styrene—in a solution of soapy water. In combining, they form a basic latex similar to that o»f natural rubber. 6. After the proper amount of chemical reaction has taken place, thoroughly uniting butadiene and
Scene in the Defense Plant Corporation Buna S synthetic rubber plant operated by the Copolymer Corp. R. K. Davies, J . V . Forrestal, W. M . Jeffers,. and R. Patterson examine Buna S which has just been copolymerized and is ready for the baler.
CHEMICAL
programs. Originally it was thought that these could produce butadiene much more quickly than the Standard plants which were being built from the ground up. These hopes have in some cases not materialized, but it is current opinion that the success of the dehydrogenation plantshas made additional conversion unnecessary. Jeffers expects all plants in the synthetic rubber program to be in production before the end of the year. At present, of the 84 separate units making up the 48 plants in the program, 27 are in operation or are ready for operation. These plants have a capacity of 252,000 long tons (30 per cent of the program), while 14 per cent of the butadiene and 18 per cent of the styrene programs are in operation. At Baton Rouge, Standard has two socalled refinery conversion plants. The first of the two was completed in January 1942 and was the first full-size oil cracking plant designed to produce butadiene and to purify it for use in Buna production. It was the principal basis for the "quickie" (refinery conversion) program. In addition to rubber raw materials, these units supply cracked gases for aviation gasoline, AND
ENGINEERING
NEWS
RUBBER IS MADE AT THE COPOLYMER PLANT styrene a chemical is added to halt the uniting process, and an antioxidant is introduced as a preservative. This step is much the same as developing a photographic print where a chemical is added to stop the action of the developing solution. 7. By adding salt and sulfuric acid the liquid latex is congealed into small rubber particles. The
process is like that of curdling milk. 8. The small rubber particles are run through a filter which absorbs the excess liquid. 9. Dryers evaporate all remaining moisture in the synthetic rubber. It is now ready for baling. 10. The synthetic leaves Copolymer in chunks ready to be processed into tires, belts, and other materials.
for tetraethyllead, and for some 20,000,000 gallons per year of synthetic alcohol. Under the "quickie" program added to the original rubber program by the Baruch committee in-September 1942, Standard rushed and put into operation in March of this year a plant capable of turning out 6,800 tons of butadiene per year. It was made b y converting regular gasolineproducing equipment to the new process without using any significant quantity of critical material. Four regular cracking units were taken in January from motor gasoline manufacture and were converted into the high-temperature cracker.
Bibliography (1) Fisher,H. L., CHBM. ENQ. NEWS, 21, 741
(1943). (2) Ibid., p. 745. (3) Murphree, E. V., Jnd. Eng. Chem.t 35, 623 (1943). (4) Murphy, W. J., CHBM. ENG. NEWS, 21,
863 (1943).
Additional pictures of Standard O i l C o . of Louisiana's catalytic cracking plant and also th« synthetic robber plat, appear on pages 9 8 6 and 9 8 7 (The Chemical News Parade).
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Butyl rubber, the second synthetic rubber invented in the United States, is shown roiling out of an extrudins machine at the Baton Rouge refinery. The production of Butyl rubber at this refinery is expected to reach 38,000 tons by the end of 1943. »
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1943
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