TORREYA 



Vol. 44 July 1944 No. 2 



Western Hemisphere Natural Rubber* 



W. Gordon Whaley 



In 1940 the United States imported some 818,000 long tons of rubber, 

 valued at $318,000,000. Of this amount 650,000 long tons were used within 

 the country. Ninety-seven percent of this rubber came from the Far East. 

 The outbreak of war in the Pacific and the subsequent loss by the Allied 

 Nations of Malaya and the East Indies thus deprived us of the main source 

 of a strategic material, the indispensability of which, already familiar, has 

 loomed larger with each day of war. By the time war came the seriousness of 

 the rubber situation had begun to be realized and certain steps were taken 

 to meet the crisis. These steps were along two different approaches — the 

 building of a synthetic rubber industry, and the development and exploitation 

 of sources of natural rubber within the Western Hemisphere. 



The construction of four 2500-ton capacity, government-owned synthetic 

 rubber plants was authorized in 1941. Around this nucleus has been built the 

 industry which it is estimated will produce some 800,000 tons of synthetic 

 rubber in 1944. 



The history of the development of synthetic rubber is almost as long as 

 the period of commercial utilization of rubber. An outline of the early steps 

 is given by H. & R. Wolf (1936). There had been several attempts to analyze 

 rubber in the early 19th century, none of them very revealing. Then in 1860 

 Greville Williams isolated a low-boiling point fraction which he named 

 isoprene. From this isoprene Williams was able to build up, by polymerization, 

 a substance having some of the properties of rubber. Several other investiga- 

 tors subsequently pointed out the apparent relation between isoprene and 

 rubber and by 1880 the production of isoprene from simple materials was 

 thought to be the only step necessary to make the production of synthetic 

 rubbers practical. Between 1882 and 1884 a process for the manufacture of 

 isoprene from turpentine was perfected. The step from isoprene to a rubber- 

 like compound proved too time-consuming, however, until in 1910 it was 

 found that sodium metal would bring about polymerization. In that year the 

 manufacture of isoprene rubber from methyl isoprene produced from acetone 

 with the aid of sodium was begun in Germany. 



* Presented at the meeting of the Torrey Botanical Club on February 1, 1944 at 

 Columbia University, New York, N. Y. 



Torreya for July (Vol. 44, 17-44) was issued July 21. 1944. 



17 



