J*70 



378 



THE INDIA RUBBER WORLD 



[April 1. 1915. 



A Review of Recent Progress in Rubber Chemistry III. 



Contributed. 



The author of this paper, a well known rubber chemist, submitted it, not as in any way a descriptive article, but merely as an 

 index of progress during the last tzvo years. To elaborate it and make it a readable article zvould necessitate the use of many 

 hundreds of pages. 



ANALYSIS OF RUBBER VXD COMPOUNDS 



THE methods used for rubber analysis in the Bureau 

 of Standards at Washington have recently been 

 published. (Thj India Rubber World, December, 1914, 

 p 126.) The report of the Joint ( ommittee on Rubber Insulation 

 Analysis has been published in the Journal of Industrial and En- 

 gineei i-.tr (vol. 6, p. 514. and The India Rui 



World, April, 1914, p. 329) The Bureau of Standards has 

 also published a method of determining caoutchouc b\ 

 direct combustion. (The India Ri bber World. September, 1914. 

 i i I Felix Jacobson i I he India Ri bbes Wi rld, December, 

 1913) has given the standard method of analysis adopted by the 

 General Electric Engineering Association of I ngland. W. Jones 

 i I mi [ndia Rubber World, September, 1913) and II. Loewen 

 i in India Ri bber World, December, 1913) have written on the 

 errors of the usual acetone determination, link (Zeitschrift 

 tischer Chimie, vol 27. 1914, p. 115) gives methods for 

 caoutchouc and gutta percha determination, II. Loewen, com- 

 menting 'Hi Jacobson's method for fillers cited above says that b\ 

 using pararfine "il heated to 230 deg., rubber sometimes separates 

 "lit. but with petroleum of B. P. 170 deg. nothing settles <>ut. 

 i India Rubber Journal. 1914, p. 83.) M. Vellen (Moniteur 

 Scientifique, 1913, vol. 3, p. SJ » claim-- that saponification will de- 

 termine fats, factice and resins in insulation, if Koetstofer's 

 method is used. Goldberg (Gummi-Zeitung, 1913, vol. 11, p 85) 

 claims that combustion in a combustion tube is accurate for carbon 

 determinations in insulation. C. Harries has done much work on 

 the identification of the eight-carbon ring, which we have pre- 

 viously referred to It is also used as a method of analysis. Later 

 he used the identification of the eight-carbon ring to determine the 

 constitution of reclaimed rubber. This same author lately has 

 made dioctyl-propane by analytical methods from the ozonides. 

 DETERMINATION OF SULPHUR. 

 E. Denser (The India Rubber World, December. 1913) has a 

 method of determining sulphur by forming the nitrosite, dissolv- 

 this in sodium carbonate, evaporating and reducing to sul- 

 phides and determining sulphur colorometrically. Herbert 

 of the Northern Polytechnic School, England, has 

 given a long review (India Rubber Journal. 1914. p 315) oi 

 the various methods of determining sulphur and prefers the 

 Kaye ind Sharpe method. Kirchof (The India Rubber World, 

 June, 1914, p. 400) has studied the addition reactions. Stevens 

 [ournal of the Society of Chemical Industry. 1914, p. 268) gives 

 the sulphur method for rubber. Utz gives his method for sulphur 

 (Gummi-Zeitung, 1914. p. 1634) I. Archbutt (Journal of the 

 Society of Chemical Industry. 1914. p. 34) claims 8 hours' 

 acetone extraction is sufficient. 



J. B. Tuttle and C. E. Water- (Journal of Industrial and En- 

 gineering Chemistry, vol. 3. i>. 734. comprising the matter in 

 Circular reprint No. 174 of Bulletin, vol. 8, No. 3, United States 

 Bureau of Standards) gives results of experiments on the vari- 

 ous sulphur methods. Their conclusions are as follows 



1st. Treatment of rubber with nitric acid alone gives low- 

 results. 



1 The Heubener method canm i bi employed on the pres- 

 ence of fillers like lead and barium compounds, which give in- 

 luble sulphates 



3rd. The Fusion methi.il gives clos< results. The van't Kruvs 

 method gives high results. 



4th. The best method is to use nitric a< id saturated with 

 bromine. 



O. Lichtenberg (Gummi-Zeitung. November, 1914, p. 222 > 



gives a contribution on the hydro-halogenides rul ier and 



their thermal dissociation. W. Schmidt (Ji the So- 

 ciety of Chemical Industry, 1914, p 614) gives bromim met 



\ G Harries (Journal of the Society of I Industry, 



1913, p. 372) describes more work on halides. I Deusen (The 



Ri bber World, December, 1913) gives I de- 

 termining rubber by nitrosides. 



FILLERS AND THEIR ANALYSIS 



V Schaeffer (Tin India Rubber World, Vpril, 1914, p. 340) 

 describes sublimed white K-ad. Gilbert Rigg> and I 1 ' Si mi 



I in India Ri bber World, May, 1913, p. 414) describe lithoj 

 and zinc oxide. Frank and Marckwald show the injurious ac- 

 tion oi copper on rubber. (The India Rubber World. August, 



1914, p. o00.) 



The Rubber Growers Association, in the "Pli 

 has recently called attention to the ruinous effects of 

 small quantities of copper on the coagulation of latex. A ■ 

 acid used for coagulation, if distilled in a cop] will 



contain injurious amounts of copper. 



Utz (The India Rubber World, February, 1914, p 224) gives a 

 method oi analysis of golden sulphite of antimony. W Schmidl 

 I India Rubber Journal, 1913, p. 83) has also this 



subject. 



Frank and Marckwald (Gummi-Zeitung, p, 1584 ia\ given 

 a method of analysis for sulphur chloride. 



F. Fritz states (Journal of the Society of Chei idustry, 



l'd4. p. 34 l that Para rubber seed oil has an iodine valui r 141. 

 convert- easily into lynoxlin and is suitable for linoleum manu- 

 facture. 



HALOGEN COMPOUNDS AND NITROSITES VN1 

 These compounds are frequently made in thf analysis of 

 caoutchouc. F. W. Hinrichsen (Report 46, p. 1203) des i 

 hydrohalides made from the acid gases. Mono ami i unds 



were made with ice: without it hexa and tetra compounds (Har- 

 ries, Journal of the Society of Chemical Industry. 1913, p. 372) 

 were made. Bromination in chloroform solution in ice gives al- 

 ways the tetrabromide. The halogens cannot always be entirely 

 removed by alcoholic potash, in boiling solution. In repeating 

 Weber'- experiment- only a green substance containing from 6 

 to 14 per cent, of iodine was obtained. 



C. R. Boggs gave a method of determining rubber by means of 

 ii< tetrabromide, at the Eighth Congres- of Chemistrj at New 

 York, 1912 (vol. 9, p. 45. Report). G. Heubner (Gummi-Zeitung. 

 vol. 28, p. 1214) has a new bromination method Vaubel and 

 Weinerth (Gummi-Zeitung, vol. 28, p "2. 1913) gi llts oi 



using the bromination method. 



W. A. Ducca (Journal of Industrial & Fngineeri -try. 



vol 4. p. 372 i has described various methods of determining the 

 caoutchouc in raw and vulcanized rubbers. He reviews Weber,. 

 Ilarrie- ami Alexander, and concludes that the niti '■ ethod 

 is of no value for determining caoutchouc but i for 



determining the co-efficient of vulcanization. 



He also reviews Budde, Marries. Rampel, llinr risen, Kind- 

 scher, Axelrod and Heubener on bromination. His wn results 

 were always high, as it is impossible to remove excess of bromine 

 by hot water. G. Heubener (India Rubber Journal, 1914. p. 

 224; Gummi-Zeitung, vol. 28, p. 320: Kolloid Zeitschrift, 1913. 

 p. 53; India Rubber Journal. 1913, p. 22) gives • work 



on bromination method and criticizes Ditmar. Caspari and 

 Kirchof. 



