10 



THE INDIA RUBBER WORLD 



[October 1, 1912. 



DR. PERKIN ON THE SYNTHESIS OF RUBBER. 



ONE of the noteworthy features of the Congress of Applied 

 Chemistry, just held in New York City was a lecture by 

 Dr. William H. Perkin, Professor of Chemistry at Victoria Uni- 

 versity, Manchester, on his researches in the field of rubber. It 

 will, therefore, be of interest to note some comments which he 

 made on this subject in the course of a subse<iuent conversation 

 with Dr. Frederic Dannerth, secretary of the Ruliber Conference. 

 Dr. Perkin's remarks are interesting, as they lack all flavor of re- 

 sentment at the attacks of his critics. 



"Dr. Duisberg," he began, "has prepared at the factory in Elber- 

 feld synthetic rubber on a considerable scale, and has supplied 

 some very valuable information concerning its physical properties. 

 It was shown in his lecture that automobile tires made up from 

 synthetic rubber outlasted similar tires made with the best Up- 

 River fine Para. 1 heartily agree with Dr. Duisberg in this asser- 

 tion, and fully appreciate the fact that an auto tire which has been 

 run over 10.000 miles and shows so little wear as the tire ex- 

 hibited by Dr. Duisberg is worthy of serious attention. I think 

 many will agree with the doctor from Elberfekl that cheap syn- 

 thetic rubber will be put on the market at a price which will enable 

 it to compete with plantation rubber possessing the same prop- 

 erties. 



"In the years 1S83 and 1884 William Tilden, then professor at 

 Mason College. Birmingham, England, prepared large quantities 

 of isoprene from turpentine. Some of this he used for his experi- 

 ments on isoprene at that time, and the remainder he either 

 bottled up or sealed up in tubes which were set aside. 



"On looking at these specimens in the year 1892 he found — to 

 his great astonishment — that this isoprene had become polymer- 

 ized to a rubber-like substance which we now know as 'synthetic' 

 rubber. The specimens exhibited by me in my lecture were the 

 original products prepared by Tilden, and those undoubtedly 

 contained synthetic rubber. This is proved by the fact that by 

 mixing the specimens with acetone true synthetic rubber is pre- 

 cipitated. We must not forget that Tilden worked under condi- 

 tions far less favorable than those which face us at the present 

 day. So that we should not wonder at the fact that some of his 

 methods were less refined than those at present used in research 

 work in this field. 



"In answering your question as to a definition for synthetic 

 rubber I would suggest : 'Isoprene, polymerized to a rubber-like 

 substance.' Since Tilden, in 1892, had polymerized isoprene to 

 a rubber-like substance, which he proved was capable of vulcan- 

 ization, it is obvious that he had synthetic rubber in his hands in 

 1892. This you will note was seventeen years before Hofmann 

 published the results which he obtained in the Elberfeld factory. 



■'.\n attempt has been made to underrate these observations 

 made by Tilden on the basis of the difference between discovery 

 and invention. In this connection it is interesting to note the 

 attitude of Professor Bernthsen of the Badische Fabrik in Lud- 

 wigshafen. Genuany. He says, 'If there is any difference be- 

 tween the invention and the discovery of synthetic rubber it is 

 obviously a small one, and in discussing a matter of this im- 

 portance Dr. Duisberg will no doubt wish to avoid any nusinter- 

 pretation of his remarks. The factory in Ludwigshafen is not at 

 this time desirous of publishing its results." 



Continuing his comments. Dr. Perkin further said : "I 

 viewed with considerable interest the wonderful specimens 

 of manufactured rubber goods made from synthetic rubber. 

 First, the tire which had been subjected to the practical road 

 test of 10,000 miles, and a new tire recently vulcanized. In addi- 

 tion to these exhibits we certainly all admired the hemisphere of 

 raw synthetic rubber of unusual density and translucency. This 

 Iwmisphere was said to weigh about 60 pounds, and was made 

 from isoprene by the sodium polymerization method. Lsoprene. 

 as most of us know, boils at 37 degrees Centigrade, so that it is 



rather difficult to transport it or keep specimens of this material 

 in other than sealed containers. 



"I'rom all present indications a retinemcnt of the present 

 methods of working will make the ultimate price of synthetic 

 rubber so low that it will compete with the plantation rubber 

 having similar properties. We should be careful, however, not to 

 be too sanguine and by our prophecies make possible a manipula- 

 tion of the stock market in either direction. I note that previous 

 remarks on the possibility of synthetic rubber have awakened in 

 the fertile minds of stock market manipulators thoughts which 

 no scientist ever had. 



"There is one fundamental discovery connected with the Man- 

 chester method for the production of synthetic rubber. It is the 

 observation by Professor Fernbach of the Pasteur Institute of 

 Paris that it is possible to ferment starch — or even sawdust, in 

 such a way as to obtain large yields of butyl alcohol and acetone 

 at prices far below the present market on these materials. Of 

 the three methods described for the synthesis of rubber which I 

 described in my London lecture, there is one which appears to be 

 of direct commercial importance. Briefly summarized it is as 

 follows: (1) Take ethyl alcohol, which may be easily oxidized 

 to acetaldehydc. (2) Condense this by means of potassium car- 

 bonate to aldol. (3) Convert the aldol (quantitatively) into 

 butylene glycol. (4) Convert the butyl ene glycol into di-chlor- 

 ide. (5) Then pass this over soda lime and produce butadiene. 

 (6) This when treated by the sodium method, yields a synthetic 

 rubber equal — if not superior — to that obtained from isoprene. 

 The work which has been accomplished at Manchester by me may 

 be summed up by saying that a rapid and satisfactory method of 

 polymerizing isoprene into normal rubber of five carbon atoms 

 has been found. The problem of producing isoprene cheaply has 

 not vet been solved." 



A BRAZILIAN VIEW OF ARTIFICIAL RUBBER. 



IN discussing the subject of artificial rubber in a recent issue, 

 the "Follia del Norte" of Para, remarks that the ideal pur- 

 sued by modern chemistry, is to replace syntheses — derived from 

 natural products, by laboratory syntheses, identical in quality 

 with the original articles. 



At various times, the journal remarks, it has been announced 

 to the world that the synthesis of rubber w-as an accomplished 

 fact. In all cases the result has been purely theoretical, or has 

 led up to the question as to what would be the expense involved 

 by carrying out the process on a large scale. Reference is made 

 to the interest aroused in July, 1911. by the announcement that 

 the firm of F. Bayer & Co.. the well-known manufacturing chem- 

 ists, expected to be successful in the work of producing synthetic 

 rubber, to which it had long been devoted. 



The importance of this statement was generally recognized; 

 it being a well known fact that German chemical manufacturers 

 regarded the production of the first pound of synthetic rubber 

 as the point to be aimed at. The cost of making tons of it would 

 have to be the subject of further investigation. 



While recognizing the injury which the production of a perfect 

 substitute for rubber would do to the natural article, it is urged 

 that such a disaster would never extinguish the Brazilian rubber 

 industry. Reference is made to the opinions expressed by chem- 

 ists of eminence, to the effect that no artificial product can ever 

 be substituted for Para rubber; the former being lacking in the 

 necessary qualities of resistance, elasticity, and homogeneous 

 composition. 



While this article was apparently written before the public an- 

 nouncement of the Perkin process, it is none the less interesting 

 as showing how the question of synthetic rubber is regarded by 

 the South .American rubber industry. 



Should be on every rubber man's desk — The Rubber Trade 

 Directorv of The World, 1912. 



