44 



KNOWLEDGE. 



February, 1913. 



two hydrogen atoms are replaced by two methyl 

 groups, thus : — 



CH 2 = CH-CH = CH 2 CH2=C (CH,)-C (CH,) = CH, 



Butadiene. /i-7-Dimethyl butadiene, dipropylene*-- 



isopropylene. 



Dimethylbutadiene is also a volatile liquid, boiling 

 at 71°C, and can be turned into a rubber by treating 

 with sodium, thus : — 



CH., = C(CH,)- 



CH S =C(CH,,)-C(CH:,I 



Dimethylbutadiene. 



C(CH ; ,)=CH :i 

 CH, 



.odium. /^Hi CICH;:)- 



VCH 2 -C(CH,) = 



Dimethylbutadi 



The rubber thus produced — a white tough leathery 

 mass — can by vulcanisation be made to yield a 

 beautifully elastic substance; unfortunately, however, 



Agriculture 



ethyl and even phenyl and naphthalene radicles 

 replace the hydrogen of butadiene. So long ago as 

 1904, Klages and Lauk showed that phenyl isoprene, 

 CH 2 = C (CH 3 )-C (C«H B ) = CH a could be made to 

 produce ebonite-like bodies on vulcanisation. 



There is thus opened up a rich field of research in 

 the production of these " super-rubbers " from which 

 a veritable mine of ebonite substitutes, bone substi- 

 C(CH)-CH» tutes, insulators, enamels, or even 

 | "\ hornlike artificial glasses, may in 

 C(CH,) — CHJx the future be manufactured, and an 

 industry be created in these pro- 

 ducts rivalling that of the coal tar dyes — an industry 

 which also had its origin in investigations connected 

 with the apparently useless products of coal tar. 



Wood 



I 



Newspaper 



Cellulose 



Acetic Acetone 



Acld Old method, 

 £90 per ton 



Potatoes and Cereals 



I 



Starch or Sugar 



Artificial Celluloid 

 Leather 



Explosives 



By two fermentation 

 processes 



By fermentation 

 (old method) 



Acetone 



New method, 

 1 30 per ton 



Butyl Alcohol 



Fusel Oil 

 £30 

 per ton 



Alcohol 



I 

 Beverages 



Amyl Alcohol 

 Fusel Oils 



Explosives Isoprene Butadiene 



I I 



Rubber. Rubber. 



Aldehyde 



1 

 I 



Butadiene 



I 

 Rubber. 



Chemical (Oldmethod"=ifl40 per ton) 



Industries \ 



/ 



Nitro- Scents 

 Isoprene cellulose 

 Varnishes 

 Rubber. 



Table 10. 



on allowing the vulcanised product to stand in the 

 air it turns into a sticky mass. Perhaps in the near 

 future experiment may overcome this difficulty and 

 the substance may yet, for special purposes, attain 

 technical importance. Dimethylbutadiene or dipro- 

 pylene is obtained from acetone by reducing it to 

 pinacone by means of magnesium amalgam, and 

 then passing the pinacone over heated potassium 

 bisulphate, which withdraws the elements of water 

 from it, thus : — 



Indeed, no man can foresee the consequences of 

 the research work now being pushed forward with 

 such vigour in every direction in this new field of 

 synthetic chemistry. 



Let us hope, however, that these new industries 

 will remain in Great Britain and not pass, like the 

 coal tar dye industry, out of our hands into those of 

 the highly-trained scientific Germans, merely because 

 British manufacturers were too ignorant to employ 

 proper research chemists in a chemical industry, and 

 CH : , Utterly despised the value of science applied 

 to industrv. We have had a shock in this 

 direction, and let us hope that British manu- 

 facturers have now had this home truth 

 driven home — that Science and Industry go 

 hand in hand, and that pre-eminence in the 

 one spells pre-eminence in the other. 



And now a word about the attitude of the 

 "Practical man" towards these new industries. 

 . I cannot do better than quote a few 



Dr. Fritz Hofmann, of Fr. Bayer, Elberfeld, has opinions which these " practical men " have pub- 

 produced a whole series of similar rubbers, in which lished in trade or technical journals. 



CH„ /CH, 



>C:0+0:C<( 



CH:,' ' CU, 



2 Molecules of Acetone. 



Nascent 



CH, 



CH,* 



>C(OH)-C(OH)< 

 Pinacone. 



KHSO, 



\;h 



Dimethylbutadiene Rubber. -4~ 



Sodii 



CH, 



\ 



/ 



CH, 



Dimethylbutadiene. 



