36 



KNOWLEDGE. 



January, 1913. 



a well-known figure in German aristocratic circles. 

 At the present time he, it is believed, is working in 

 conjunction with some of the world-famous German 

 chemical firms with the object of producing synthetic 

 rubber commercially. 



Harries' work was really epoch-making in every 

 way. He indicated the probable constitution of 

 rubber, reducing it to a simple formula ; he showed 

 how to prove chemically whether a substance was a 

 true rubber or not, and indirectly his researches 

 drew the attention of the chemical world to the 

 enormous prizes to be won by the successful 

 synthetic production of rubber. The stimulus 

 produced by Harries' work, coupled with the high 

 price of natural rubber, soon reflected itself in 

 industrial chemical circles, and from 1907 onwards 

 the patent literature bears witness to the extraordinary 

 activity reigning in this department of chemistry. 



Among the large continental firms which took 

 part in the race were Fr. Bayer & Co., of Elberfeld, 

 Germany, the Badische Aniline und Soda Fabrik, of 

 Ludwigshafen, and Messrs. Schering, of Berlin. A 

 photograph of Dr. Fritz Hofmann, who directed the 

 work of the chemists of Fr. Bayer & Co., is shown 

 in Figure 35. 



Meanwhile in England the firm of Messrs. Strange 

 and Graham united with a number of chemists of 

 note with a view to produce synthetic rubber, and 

 so the " Synthetic Products Co. " of London came 

 into existence. No less than fifteen chemists and 

 bacteriologists were thus united at work on the 

 problem. Foremost among these chemists must be 

 mentioned Dr. F. E. Matthews (Figure 36), of the 

 firm of Strange & Graham, who suggested the fusel 

 oil route for the manufacture of isoprene and who 

 was the first to discover and patent the sodium pro- 

 cess of polymerising isoprene quantitatively into 

 rubber, thereby making possible the commercial 

 manufacture of synthetic rubber. 



Mr. E. Halford Strange (Figure 37), head of the 

 firm of Strange & Graham, organised the work of 

 the group and brought into existence the company ; 

 Professor W. H. Perkin, junr., F.R.S. (Figure 38), 

 Professor of Chemistry at Manchester University, 

 with his two assistants Mr. Harold Davies and Dr. 

 Weizmann, perfected the chemical processes 

 ployed in pro- 

 ducing isoprene. 

 Professor Perkin 

 is the son of 

 the famous Sir 

 William Perkin, 

 who brought into 

 existence the 

 aniline dye in- 

 dustry, and made 

 a fortune out of 

 it, although sub- 

 sequently the 

 colour industry 

 went over into 

 German hands. Table 6. 



Professor Perkin, who has produced an enormous 

 quantity of research work of the highest quality in 

 pure chemistry, has evidently inherited the practical 

 abilities of his father ; for he, a few years ago, 

 invented the " non-flam " process for permanently 

 fireproofing cotton goods. 



Professor A. Fernbach (Figure 39), of the Pasteur 

 Institute, succeeded in producing acetone and fusel 

 oils cheaply by a process of fermentation from 

 cereals, thereby producing the raw material for the 

 manufacture of synthetic rubber. 



Later, the group was joined by Sir William 

 Ramsay (Figure 41), the famous discover of Argon, 

 Helium and other inert atmospheric gases ; it will be 

 recollected that Sir William Ramsay quite recently 

 resigned his professorship of chemistry at University 

 College, London, about the same time that the 

 company was formed. 



Sir W. A. Tilden (Figure 33) also joined the com- 

 pany as a consulting chemist. It will be recollected 

 that Sir William Tilden nearly thirty years ago 

 had performed some epoch-making work on isoprene, 

 and the formation of synthetic rubber from it. 



Before we can give an account of the chemical 

 processes for producing synthetic rubber commerci- 

 ally, we must explain its chemical constitution. 



The net result of a vast amount of research work 

 performed by various investigators, has been to show 

 that when certain unsaturated hydrocarbons contain- 

 ing the grouping : C : C.C : C : are allowed to 

 polymerise (i.e., condense into more complicated 

 bodies) they form a series of caoutchoucs or rubbers 

 which possess many of the properties of the best 

 sorts of natural rubber, including the power of 

 vulcanising. Natural rubber is the rubber produced 

 by the polymerisation of one particular hydrocarbon 

 called isoprene ; but the chemical sisters and brothers, 

 so to speak, of isoprene all produce rubbers of 

 different sorts, some of them with new and valuable 

 properties for special purposes. 



The hydrocarbons from which technical synthetic 

 rubber have been formed are : — 



Butadiene (Ervthrene, Divinyl), CH 2 = CH — CH 

 = CH 2 . 



fi-Methyl butadiene (isoprene, methyl divinyl), 



em- CH 2 = C(CH 8 )-CH = CH 2 



CH,=CH-CH=CH 5 



— > 



CH 2 =CH-CH= 

 Butadiene. 

 CH 2 =C(CH„)-CH 



CH, 



= CH. ; 



CH 2 =CH-C(CH 3 ) = CH 2 

 /3- Methyl butadiene (isoprene). 



CH 2 = C(CH 8 )-C(CH 3 )=CH 2 



CH 2 =C(CH 3 )-C(CH 3 ) = CH 2 



|3-7-Dimethyl butadiene 

 (di-isopropylene, dipropylene). 



CH 2 -CH=CH-CH, 



I I 



CH 2 -CH = CH-CH 2 ' ) 



Normal butadiene rubber 

 CH 2 -C(CH 3 ) = CH-CH.. 



I I 



CH 2 -CH = C(CH„)-CH ; 



/3-Methyl butadiene rubber 

 (isoprene rubber, natural rubber) 



CH 2 -C(CH«) = C(CH a )-CH., 



I I 



CH 2 -C(CH 8 ) = C(CHa)-CH 2 

 /S-7- Dimethyl butadiene rubber 

 (dipropylene rubber). 



f}-y- Dimethyl 



butadiene (di- 

 isopropylene, di- 

 propvlene), CH 2 

 = C(CH 8 )— C 

 (CH 8 ) = CH a . 



The first sub- 

 stance is at or- 

 dinary tempera- 

 tures a gas, 

 but readily con- 

 denseson cooling 

 to a volatile 

 liquid. The other 

 two substances 

 are volatile 



