scholarly journals THE DETERMINATION OF BARIUM CARBONATE AND BARIUM SULFATE IN VULCANIZED RUBBER GOODS

1916 ◽  
Vol 8 (4) ◽  
pp. 324-326
Author(s):  
John B. Tuttle
Keyword(s):  
Barium Sulfate ◽  
Barium Carbonate ◽  
Vulcanized Rubber

Determination of Total Sulfur in Vulcanized Rubber Mixtures

1952 ◽  
Vol 25 (2) ◽  
pp. 371-374 ◽  
Author(s):  
Horst Frey
Keyword(s):  
Iron Oxide ◽  
Ion Exchange ◽  
Barium Sulfate ◽  
Aqueous Sodium Hydroxide ◽  
Total Sulfur ◽  
Aqueous Sodium ◽  
Vulcanized Rubber ◽  
Exchange Agent ◽  
Volumetric Methods

Abstract A method is described, which, by means of a resin ion-exchange agent, makes possible the elimination of the disturbing effects of foreign cations, particularly iron and chromium, in the determination of the total sulfur in vulcanized rubber mixtures. By this procedure, rapid volumetric methods for determining sulfate, even in the analysis of mixtures containing iron oxide or chromium oxide pigments, can be utilized. The procedure involves precipitation of the sulfate by benzidine and determination by titration with aqueous sodium hydroxide. The method is more rapid and more reliable than ordinary gravimetric methods involving precipitation of barium sulfate.

Determination of Free Sulfur in Vulcanized Rubber

1942 ◽  
Vol 15 (2) ◽  
pp. 376-377
Author(s):  
J. G. Mackay ◽  
C. H. J. Avons
Keyword(s):  
Nitric Acid ◽  
Hydrochloric Acid ◽  
Barium Sulfate ◽  
Barium Chloride ◽  
Acetone Extract ◽  
Volumetric Method ◽  
Watch Glass ◽  
Rubber Industry ◽  
Vulcanized Rubber

Abstract The following comments pertain to a paper of the above title by Mackay and Avons, published in Transactions of the Institution of the Rubber Industry, Vol. 16, pages 117–122, October 1940, and reprinted in Rubber Chemistry and Technology, Vol. 14, pages 520–524, April 1941. H. P. Stevens draws attention to the penultimate paragraph on p. 522 in which it is pointed out that the bromine method of oxidation is tedious and the reagent unhealthful, whereas perchloric acid may be dangerous. As a result of many years experience he is of the opinion that neither reagent is necessary. After adding nitric acid to the acetone extract in the flask, which should be covered with a watch glass, and when the reaction has subsided, about 0.5 gram of potassium chlorate is added and the mixture kept warm at 50 to 60° C. The top of a water oven is convenient; but the heating must be limited, as the yellow oxides of chlorine are rapidly driven off near 100°, and the liquid changes back from yellow to orange. The flask can be left to itself for an hour or two, but further addition of chlorate may be necessary to complete the oxidation. The contents are evaporated to dryness and taken up twice with concentrated hydrochloric acid preparatory to precipitation with barium chloride. A volumetric method may be preferable when a large number of routine tests have to be made, otherwise the final estimation can be made as barium sulfate.

Sign in / Sign up

Export Citation Format

Share Document