HISTORICAL SKETCH OF CHEMISTRY OF RUBBER n 



occurred to him to seal up some isoprene with sodium. Reluc- 

 tantly returning to town during a holiday in August, he dis- 

 covered that the tube contained a portion of remarkably good 

 rubber. By September the contents had set to a solid amber- 

 coloured mass. Further work indicated the importance of 

 sodium as a general polymerising agent for these hydrocarbons, 

 and a patent was applied for on October 25, three months 

 before the German application. 



While possessing the same physical properties as synthetic 

 rubbers produced by other methods, the rubbers obtained by 

 the action of sodium appear to have a somewhat different 

 chemical constitution. Ozonides are formed less readily, and 

 give rise to other products than laevulinic acid and aldehyde. 

 The constitution of sodium isoprene caoutchouc is believed 

 to be dimethylcyclooctadiene with conjugated ethylenic 

 linkages. 



As the result of these researches it is hoped that before long 

 synthetic rubber will be placed on the market. 









