The Bell System Technical Journal 



Vol. XXV July, 1^46 No. 3 



Some Recent Contributions to Synthetic Rubber Research* 



By C. S. FULLER 



Introduction 



WHEN the war put an end to shipments of natural rubber from the Far 

 East, it became evident that synthetic chemistry would be called 

 upon to fill the gap in our supply of this strategic material. We know now 

 how effectively the emergency was met. In less than three years the 

 production of Buna S type synthetic rubber alone had risen to exceed our 

 total prewar comsumption of natural rubber. Few, however, realize the 

 magnitude of the effort and the extent of the cooperation between groups of 

 experts that was essential for the achievement of this success. 



Rubber companies in this country had been experimenting with synthetic 

 substitutes for natural rubber for some time before the present war began. 

 None of these products, however, was sufficiently advanced either from the 

 stand-point of raw materials or in regard to the knowledge of its properties, 

 to warrant production on a large scale as a substitute for natural rubber 

 during the emergency. In 1942, following the advice of the Baruch Com- 

 mittee, we decided to place chief reliance on Buna S, the butadiene-styrene 

 synthetic rubber which the Germans developed about 1934. In addition, 

 considerable support was given to the domestic synthetics, Neoprene, Thio- 

 kol and Butyl. The latter rubbers, however, were not considered as useful 

 for tires as Buna S. 



Making Buna S in this country and fabricating it were not simple, how- 

 ever. The Germans had kept the details of the process secret and restricted 

 shipments of the product. Besides, as we have since found out, the German 

 chemists did not have any too complete control of the process themselves 

 and the type of rubber made by them, as shown by samples obtained 

 indirectly, was not satisfactory for use on American processing machinery. 

 Our engineers and research men were therefore faced with the problem of 

 setting up a process on an enormous scale to turn out a product which could 

 be used in our tire plants and which would give satisfactory service on the 

 road. Fortunately for us, a few companies had acquired enough knowledge 



* The investigations described in this article were carried out under the sponsorship of 

 the Reconstruction Finance Corporation, Office of Rubber Reserve, in connection with 

 the Government synthetic rubber program. 



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