Kinetic Analysis of Rubber Halides

1950 ◽  
Vol 23 (2) ◽  
pp. 447-456 ◽  
Author(s):  
G. Salomon ◽  
C. Koningsberger ◽  
A. J. Ultée
Keyword(s):  
Hydrochloric Acid ◽  
Natural Rubber ◽  
Kinetic Analysis ◽  
Reaction Kinetics ◽  
Organic Halide ◽  
Organic Bases ◽  
Rate Of Reaction ◽  
Closed Systems

Abstract A correlation is established between the structure of an organic halide and its rate of reaction with a number of organic bases. Analysis by reaction kinetics, based on this correlation, is applied to the following problems. (1) Estimation of the allylic fraction in the chlorination and bromination of natural rubber. (2) Differentiation between a dichloride and a polychloride from natural rubber. (3) Determination of an equilibrium between natural rubber and hydrochloric acid at 130° C in closed systems. (4) Identification of tertiary chlorides and bromides in natural rubber and allied polymers.

Kinetic Analysis of Organic Halides. II. Analysis of Macromolecules Built up of Monohalide Units

1951 ◽  
Vol 24 (2) ◽  
pp. 436-446 ◽  
Author(s):  
G. Salomon ◽  
C. Koningsberger
Keyword(s):  
Natural Rubber ◽  
Kinetic Analysis ◽  
Vinyl Chloride ◽  
Physical Factors ◽  
Organic Bases ◽  
Synthetic Rubber ◽  
Organic Halides ◽  
First Time ◽  
Natural And Synthetic

Abstract A number of hydrochlorides of natural and synthetic rubbers and allied polymers have been prepared and subjected to kinetic analysis with organic bases. The hydrochlorides of natural rubber react at 100° C at a rate identical to that of low-molecular tertiary chlorides. At 50° C the reactivity of the polymer is, however, reduced by physical factors. The hydrochloride of GR-S (a synthetic rubber made from butadiene and styrene) has been prepared for the first time by heating the swollen polymer with HC1 under pressure. Kinetic analysis of this product revealed two fractions: the expected secondary chloride, and a small fraction of a very reactive (tertiary?) chloride. After elimination of experimental difficulties, we succeeded in the preparation and kinetic identification of the pure tertiary hydrobromide of natural rubber. Attempts to prepare the secondary bromide under peroxide conditions failed. Kinetic analysis of two types of Neoprene revealed the presence of a small quantity of allylic groups in the polymer, while 95 per cent of the chlorine in Neoprene has the expected stability of a vinyl chloride. This stability can be used for the identification of Neoprene.

Overall Kinetics of Natural Rubber Vulcanization at High Temperatures I—review of Investigation Techniques, Methods and Previous Results of Kinetic Analysis

1971 ◽  
Vol 44 (5) ◽  
pp. 1316-1325 ◽  
Author(s):  
R. B. Redding ◽  
D. A. Smith
Keyword(s):  
Natural Rubber ◽  
Kinetic Analysis ◽  
Kinetic Parameters ◽  
High Temperatures ◽  
Kinetic Data ◽  
Network Chain ◽  
Correct Determination ◽  
Kinetics Of ◽  
Overall Kinetics

Abstract Analysis of previously published cure data illustrates the importance of correct determination of the ultimate level of network chain density in the absence of reversion, and the correction of each kinetic data point for “reversion contributions”. A graphical procedure is described for the determination of kinetic parameters which takes these precautions into account.

scholarly journals The preparation of α-oxo acid derivatives suitable for specific-radioactivity determination

1970 ◽  
Vol 120 (1) ◽  
pp. 171-175 ◽  
Author(s):  
J. Mowbray ◽  
J. H. Ottaway
Keyword(s):  
Hydrochloric Acid ◽  
Initial Rate ◽  
Specific Radioactivity ◽  
Optimum Conditions ◽  
Quinoxaline Derivatives ◽  
Absorption Of Light ◽  
Rate Of Reaction ◽  
Chemical Determination ◽  
Layer Chromatography

1. Conditions favouring the condensation of o-phenylenediamine with α-oxo acids to form substituted quinoxalines have been investigated. The best yields (85–100%) are obtained by incubation of the reagents in 2m-hydrochloric acid. Substitution of acetic acid for hydrochloric acid, or of halogen-substituted 1,2-diaminobenzenes for phenylenediamine, increases the initial rate of reaction, but not the yield of quinoxalines. 2. The quinoxaline derivatives are insoluble in water and can be readily purified. They are very suitable for determination of the specific radioactivities of radioactively labelled α-oxo acids because they are colourless, soluble in dioxan-based scintillators, and their strong absorption of u.v. light facilitates their chemical determination. As little as 1 nmol can be accurately determined by means of the blue fluorescence produced by absorption of light at 340–360nm. 3. Optimum conditions for preparation, purification and separation by paper and thin-layer chromatography are described.

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