Natural and Synthetic Rubber. VIII. Products of the Destructive Distillation of Sodium Rubber

1932 ◽  
Vol 5 (1) ◽  
pp. 1-6
Author(s):  
Thomas Midgley ◽  
A. L. Henne ◽  
A. F. Shepard
Keyword(s):  
Double Bond ◽  
Natural Rubber ◽  
Ethylenic Bond ◽  
Methyl Groups ◽  
Pyrolysis Products ◽  
Synthetic Rubber ◽  
Natural And Synthetic

Abstract The pyrolysis products of sodium rubber have been compared with those of natural rubber. They indicate that sodium rubber is isomeric with natural rubber in the positioning of its methyl groups, and that the double bond of sodium rubber differs from the true ethylenic bond of natural rubber. In the latter respect sodium rubber closely resembles overvulcanized rubber.

Natural and Synthetic Rubber. IV. 4-Methyl-4-Octene by Isoprene Ethylation

1930 ◽  
Vol 3 (3) ◽  
pp. 483-484
Author(s):  
Thomas Midgley ◽  
Albert L. Henne
Keyword(s):  
Double Bond ◽  
Synthetic Rubber ◽  
Double Bond System ◽  
Bond System ◽  
Usual Behavior ◽  
Natural And Synthetic ◽  
Long Chains

Abstract Isoprene has been ethylated; 4-methyl-4-octene was formed exclusively. The structure of this nonene is in agreement with the usual behavior of a conjugated double bond system. This type of addition is further evidence in favor of the hypothesis which regards the polymerization of isoprene to synthetic rubber as the formation of long chains of isoprene units linked together- by ordinary valences in the 1,4-position.

scholarly journals Historical and Recent Achievements in the Field of Microbial Degradation of Natural and Synthetic Rubber

2012 ◽  
Vol 78 (13) ◽  
pp. 4543-4551 ◽  
Author(s):  
Meral Yikmis ◽  
Alexander Steinbüchel
Keyword(s):  
Natural Rubber ◽  
Microbial Degradation ◽  
Environmental Biotechnology ◽  
Gram Positive ◽  
Gram Negative ◽  
Content Type ◽  
Key Enzymes ◽  
Degrading Bacterium ◽  
Synthetic Rubber ◽  
Natural And Synthetic

ABSTRACTThis review intends to provide an overview of historical and recent achievements in studies of microbial degradation of natural and synthetic rubber. The main scientific focus is on the key enzymes latex-clearing protein (Lcp) from the Gram-positiveStreptomycessp. strain K30 and rubber oxygenase A (RoxA) from the Gram-negativeXanthomonassp. strain 35Y, which has been hitherto the only known rubber-degrading bacterium that does not belong to the actinomycetes. We also emphasize the importance of knowledge of biodegradation in industrial and environmental biotechnology for waste natural rubber disposal.

Natural and Synthetic Rubber. I. Products of the Destructive Distillation of Natural Rubber

1929 ◽  
Vol 2 (3) ◽  
pp. 441-451 ◽  
Author(s):  
Thomas Midgley ◽  
Albert L. Henne
Keyword(s):  
Experimental Data ◽  
Natural Rubber ◽  
Atmospheric Pressure ◽  
Experimental Results ◽  
Double Bonds ◽  
Synthetic Rubber ◽  
Single Bonds ◽  
Natural And Synthetic

Abstract Two hundred pounds of pale crepe rubber have been destructively-distilled at atmospheric pressure. The distillate was fractionated and its components identified from C5 to C10, as shown in the table. Assuming that the Staudinger formula is correct, that the single bonds furthest from the double bonds are the weaker spots and that the formation of six-carbon rings is favored, it has been shown that nearly all of the compounds actually isolated could be predicted. The experimental results, together with forthcoming experimental data, are expected to be used to throw light upon the formula of the rubber molecule.

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.

Natural and Synthetic Rubber. XIV. A Structural Formula for Ebonite

1934 ◽  
Vol 7 (3) ◽  
pp. 520-524
Author(s):  
Thomas Midgley ◽  
Albert L. Henne ◽  
A. F. Shepard
Keyword(s):  
Carbon Atom ◽  
Structural Formula ◽  
The Other ◽  
Pyrolysis Products ◽  
Methyl Group ◽  
Synthetic Rubber ◽  
The One ◽  
Natural And Synthetic

Abstract A formula for ebonite has been proposed, where sulfur is linked to a carbon atom bearing a methyl group on the one side and to the next third carbon atom of the rubber chain on the other side This formula is based on a consideration of the pyrolysis products of ebonite.

Liquid guayule natural rubber, a renewable and crosslinkable processing aid in natural and synthetic rubber compounds

2020 ◽  
Vol 276 ◽  
pp. 122933
Author(s):  
Xianjie Ren ◽  
Cindy S. Barrera ◽  
Janice L. Tardiff ◽  
Andres Gil ◽  
Katrina Cornish
Keyword(s):  
Natural Rubber ◽  
Synthetic Rubber ◽  
Rubber Compounds ◽  
Natural And Synthetic

Natural and Synthetic Rubber. II. Reduction of Isoprene by Na-Nh3

1929 ◽  
Vol 2 (3) ◽  
pp. 452-452
Author(s):  
Thomas Midgley ◽  
Albert L. Henne
Keyword(s):  
Molecular Weight ◽  
Double Bond ◽  
Low Temperature ◽  
High Molecular Weight ◽  
Liquid Ammonia ◽  
Volatile Hydrocarbon ◽  
Hydrogen Addition ◽  
Synthetic Rubber ◽  
Reaction Proceeds ◽  
Natural And Synthetic

Abstract The reduction of isoprene by sodium in liquid ammonia was attempted to determine: (1) whether reduction would take place in preference to polymerization and (2) the location of the added hydrogen. Isoprene was added to sodium dissolved in liquid ammonia and a 60% yield of 2-methyl-2-butene resulted. No other volatile hydrocarbon was found. High molecular weight hydrocarbons were formed but were not investigated. It is thus shown: (1) that the predominant reaction proceeds in accordance with the equation C5C8+2Na+2NH3=C5C10+2NaNH2 and (2) that hydrogen adds to isoprene in the 1,4-position, in agreement with Thiele's theory. The hydrogen addition is similar to the bromination of isoprene at low temperature. If properly conducted the latter reaction stops after 2 atoms of bromine have been added to 1 molecule of isoprene; the resulting compound, 1,4-dibromo-2-methyl-2-butene, is characterized b the inactivity of its double bond toward bromine. Similarly, 2-methyl-2-butene obtained by reduction of isoprene is not reduced to isopentane by an excess of Na—NH3 reagent.

Natural and Synthetic Rubber. XV. Oxygen in Rubber

1936 ◽  
Vol 9 (1) ◽  
pp. 74-82
Author(s):  
Thomas Midgley ◽  
A. L. Henne ◽  
A. F. Shepard ◽  
Mary W. Renoll
Keyword(s):  
Natural Rubber ◽  
Quantitative Data ◽  
Hydroxyl Group ◽  
Synthetic Rubber ◽  
Natural And Synthetic

Abstract It has been shown that natural rubber conthins oxygen, while synthetic rubber is oxygen free. This oxygen appears to be of an hydroxylic type, and its quantity corresponds to about one hydroxyl group for each one thousand isoprene units of the rubber molecule. Rubber has been allowed to oxidize and a mechanism is proposed to interpret the quantitative data recorded.

Effect of Temperature on Resilience of Natural and Synthetic Rubber

1943 ◽  
Vol 16 (4) ◽  
pp. 881-887
Author(s):  
H. C. Jones ◽  
E. G. Snyder
Keyword(s):  
Natural Rubber ◽  
Effect Of Temperature ◽  
Synthetic Rubber ◽  
Natural And Synthetic

Abstract The necessity of the substitution of synthetic elastomers for natural rubber has been forced on the rubber compounder by the exigencies of war. His background of a hundred years of research and compounding is his principal weapon for making this conversion in the shortest possible time. Too often he finds that this background fails and that practices invaluable in the development of natural rubber stocks are worthless in the case of synthetic rubber, or at least are subject to a different interpretation.

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