Products of Oxidation of an Olefin Structurally Related to GR-S

1953 ◽  
Vol 26 (3) ◽  
pp. 528-542 ◽  
Author(s):  
G. R. Mitchell ◽  
J. Reid Shelton
Keyword(s):  
Product Information ◽  
Probable Mechanism ◽  
Surface Coatings ◽  
Research Association ◽  
Oxidation Reactions ◽  
Structural Units ◽  
Synthetic Rubber ◽  
Considerable Portion ◽  
Oxidation Of Hydrocarbons ◽  
Oxidation Of Olefins

Abstract The fields of rubber, plastics, surface coatings, and petroleum include a considerable portion of the industrial activity of the world, and in each of these industries oxidation is an important factor in product processing and in the properties of the final product. Information regarding the nature of the oxidation reactions observed in any of these fields can be applied in part to the others. Because of the complexity of the materials involved, it is frequently desirable to study pattern molecules of comparable structure and to seek to apply the knowledge obtained in this way to the more complex systems. This investigation is a part of a research program on the nature of the oxidation of natural and synthetic rubber and related materials. It is confined to the study of an olefin, 5-phenyl-2-pentene, which represents one of the possible repeating structural units of GR-S rubber. There is considerable information in the literature regarding the probable mechanism of oxidation of hydrocarbons, both saturated and unsaturated. The oxidation of olefins, for example, has been studied extensively by workers in the laboratory of the British Rubber Producers' Research Association and the following sequence of reactions for either thermal or photoxidation with molecular oxygen was proposed:

Oxidation of Olefins Representing Some Structural Units of GR-S

1952 ◽  
Vol 25 (1) ◽  
pp. 21-32 ◽  
Author(s):  
W. C. Warner ◽  
J. Reid Shelton
Keyword(s):  
Phenyl Group ◽  
Kinetic Mechanism ◽  
Oxidation Reactions ◽  
Chain Reaction ◽  
Instantaneous Rate ◽  
Initial Oxygen ◽  
Oxidation Of Olefins ◽  
A Minor ◽  
The Relationship ◽  
Kinetics Of

Abstract Three olefins were oxidized in the liquid phase with molecular oxygen to determine the kinetics of the oxidation reactions and the relationship to oxidation of rubber. The instantaneous rate of oxidation was found to be related to the analytically determined olefin and peroxide concentrations by the equation : Rate=k (unreacted olefin)(peroxide), where rate equals moles of oxygen per mole of original olefin per hour and the parentheses represent molarities. Presence of a phenyl group was found to affect k, but only in a minor way, indicating that the same fundamental kinetic mechanism applies in both aromatic and aliphatic olefins. The data are consistent with the general kinetic mechanism of Bolland involving oxygen attack at the alpha-methylenic group. However, it appears probable that initial oxygen attack can also occur at the double bond, resulting in the formation of a peroxide biradical, which may then react with other olefin molecules, initiating the usual chain reaction mechanism.

scholarly journals Further investigations on the kinetics of gaseous oxidation reactions

1930 ◽  
Vol 129 (810) ◽  
pp. 284-299 ◽  
Keyword(s):  
Rate Of Change ◽  
Chain Mechanism ◽  
Oxidation Reactions ◽  
Chain Reactions ◽  
Oxidation Of Methane ◽  
Simple Order ◽  
Oxidation Of Hydrocarbons ◽  
Rate Of Reaction ◽  
A Chain ◽  
Kinetics Of

Investigation of the kinetics of the oxidation of ethylene and of benzene showed that these reactions are peculiar in the following respects. First, the relation between the rate of reaction and concentration is such that the reactions possess no simple “order,” though the nearest integral value for the order is about the third of fourth. The rate increases very rapidly with increasing hydrocarbon concentration, but is relatively little influenced by oxygen; under some conditions oxygen may have a retarding influence. Secondly, the reactions can be slowed down by increasing the surface exposed to the gases. This indicates that the oxidation occurs by a chain mechanism. Thirdly, the rate of change of pressure accompanying the oxidation only attains its full value after an induction period, during which evidently intermediate products are accumulating. Accepting the fact that the oxidations are probably chain reactions, the relation between rate and concentration shown that the chains are much more easily propagated when the intermediate active molecules encounter more hydrocarbon than when they encounter oxygen. Following the view of Egerton, and consistently with previous work on the combination of hydrogen and oxygen, the working hypothesis adopted is that some intermediate peroxidised substance is responsible for the propagation of the chains. This being so, the question arises whether the peculiarities found in the oxidation of hydrocarbons will also be found with substances already containing oxygen. To investigate, therefore, the influence of chemical configuration on the mechanism of oxidation reactions the following series of compounds has been studied CH 4 CH 3 OH HCHO which represent the stages through which Bone and others have shown the oxidation of methane to occur.

scholarly journals The kinetics of the oxidation of gaseous benzene

1930 ◽  
Vol 127 (804) ◽  
pp. 218-227 ◽  
Keyword(s):  
High Ratio ◽  
Chain Mechanism ◽  
Homogeneous Reaction ◽  
Oxidation Reactions ◽  
High Concentration ◽  
Ethylene Concentration ◽  
Oxidation Of Hydrocarbons ◽  
Kinetics Of ◽  
Gaseous Benzene ◽  
Oxidation Of Benzene

The comparatively few exothermic gaseous oxidation reactions which have been investigated kinetically nearly all exhibit interesting peculiarities of behaviour connected with the existence of the “chain” mechanism. The oxidation of hydrocarbons is an example to which considerable attention is at present being given. The rate of oxidation is sometimes retarded by an increase in the surface of the containing vessel—a fact which points directly to the existence of reaction chains—and the relation between the rate and the concentrations of the gases is often a remarkable one. Thus ethylene is oxidised at a speed which is relatively little affected by the oxygen concentration but depends upon a high power of the ethylene concentration. Similar relations hold good for acetylene, It seemed, therefore, of interest to study the oxidation of gaseous benzene, partly to ascertain what would be the behaviour of a hydrocarbon of a quite different kind of structure, and partly because benzene is a substance of inherent chemical importance. The results indicate that the oxidation of benzene is a homogeneous reaction in which chains play a part, though not so important a part as, for example, in the combination of hydrogen and oxygen. Kinetically the reaction resembles the oxidation of ethylene in many respects. In particular, rapid oxidation both of benzene and ethylene is markedly favoured by a high concentration of the hydrocarbon, and, other things being equal, by a high ratio of hydrocarbon to oxygen. From this it appears that the primary product of oxidation gives rise to chains by reacting with more hydrocarbon, but not so readily by reacting with oxygen.

Oxidation reactions catalyzed by osmium compounds. Part 4. Highly efficient oxidation of hydrocarbons and alcohols including glycerol by the H2O2/Os3(CO)12/pyridine reagent

RSC Advances ◽  
2013 ◽  
Vol 3 (35) ◽  
pp. 15065 ◽  
Author(s):  
Georgiy B. Shul'pin ◽  
Yuriy N. Kozlov ◽  
Lidia S. Shul'pina ◽  
Wagner A. Carvalho ◽  
Dalmo Mandelli
Keyword(s):  
Oxidation Reactions ◽  
Highly Efficient ◽  
Oxidation Of Hydrocarbons

scholarly journals Biologically inspired oxidation catalysis using metallopeptides

2018 ◽  
Vol 47 (6) ◽  
pp. 1755-1763 ◽  
Author(s):  
Laia Vicens ◽  
Miquel Costas
Keyword(s):  
High Efficiency ◽  
Coordination Complexes ◽  
Oxidation Catalysis ◽  
Metal Coordination ◽  
Oxidation Reactions ◽  
Biologically Inspired ◽  
Promising Strategy ◽  
Oxidation Of Hydrocarbons

Metalloenzymes can catalyze the oxidation of hydrocarbons with high efficiency and selectivity. For this reason, they are taken as inspiration for the development of new catalyst. A promising strategy is the combination of metal coordination complexes and peptide chains. The use of metallopeptides in oxidation reactions is discussed.

Activating earth-abundant electrocatalysts for efficient, low-cost hydrogen evolution/oxidation: sub-monolayer platinum coatings on titanium tungsten carbide nanoparticles

2016 ◽  
Vol 9 (10) ◽  
pp. 3290-3301 ◽  
Author(s):  
Sean T. Hunt ◽  
Maria Milina ◽  
Zhenshu Wang ◽  
Yuriy Román-Leshkov
Keyword(s):  
Tungsten Carbide ◽  
Hydrogen Evolution ◽  
Low Cost ◽  
Surface Coatings ◽  
Oxidation Reactions ◽  
Acidic Media ◽  
Platinum Surface ◽  
Earth Abundant

Decorating titanium tungsten carbide nanoparticles with sub-monolayer platinum surface coatings yields efficient and stable catalysts for hydrogen evolution/oxidation reactions in acidic media.

Novel, benign, solid catalysts for the oxidation of hydrocarbons

2005 ◽  
Vol 363 (1829) ◽  
pp. 1001-1012 ◽  
Author(s):  
Paul Ratnasamy ◽  
Robert Raja ◽  
Darbha Srinivas
Keyword(s):  
Catalytic Activity ◽  
Molecular Sieves ◽  
Metal Ion ◽  
Copper Phthalocyanine ◽  
Zeolite Y ◽  
Copper Acetate ◽  
Porous Solids ◽  
Oxidation Reactions ◽  
Solid Catalysts ◽  
Oxidation Of Hydrocarbons

The catalytic properties of two classes of solid catalysts for the oxidation of hydrocarbons in the liquid phase are discussed: (i) microporous solids, encapsulating transition metal complexes in their cavities and (ii) titanosilicate molecular sieves. Copper acetate dimers encapsulated in molecular sieves Y, MCM-22 and VPI-5 use dioxygen to regioselectively ortho -hydroxylate l -tyrosine to l -dopa, phenol to catechol and cresols to the corresponding o -dihydroxy and o -quinone compounds. Monomeric copper phthalocyanine and salen complexes entrapped in zeolite-Y oxidize methane to methanol, toluene to cresols, naphthalene to naphthols, xylene to xylenols and phenol to diphenols. Trimeric μ 3 -oxo-bridged Co/Mn cluster complexes, encapsulated inside Y-zeolite, oxidize para -xylene, almost quantitatively, to terephthalic acid. In almost all cases, the intrinsic catalytic activity (turnover frequency) of the metal complex is enhanced very significantly, upon encapsulation in the porous solids. Spectroscopic and electrochemical studies suggest that the geometric distortions of the complex on encapsulation change the electron density at the metal ion site and its redox behaviour, thereby influencing its catalytic activity and selectivity in oxidation reactions. Titanosilicate molecular sieves can oxidize hydrocarbons using dioxygen when loaded with transition metals like Pd, Au or Ag. The structure of surface Ti ions and the type of oxo-Ti species generated on contact with oxidants depend on several factors including the method of zeolite synthesis, zeolite structure, solvent, temperature and oxidant. Although, similar oxo-Ti species are present on all the titanosilicates, their relative concentrations vary among different structures and determine the product selectivity.

Chemical Aspects of In-Situ Combustion - Heat of Combustion and Kinetics

1972 ◽  
Vol 12 (05) ◽  
pp. 410-422 ◽  
Author(s):  
J.G. Burger
Keyword(s):  
Porous Media ◽  
Combustion Front ◽  
Combustion Process ◽  
Heat Of Combustion ◽  
Oxidation Reactions ◽  
In Situ Combustion ◽  
Oxidation Of Hydrocarbons ◽  
Kinetics Of ◽  
Heat Released

Abstract General remarks on the oxidation reactions of hydrocarbons involved in in-situ combustion are followed by estimates of heat releases. A formula is derived for computing the heat of combustion in the high-temperature zone. Reaction kinetics in porous media applied to the in-situ combustion porous media applied to the in-situ combustion process is discussed. It is observed that there is process is discussed. It is observed that there is some similarity between the kinetics of reverse and partially quenched combustion processes. The influence of additives on crude oil oxidation in porous media is illustrated by effluent gas analysis experiments. Some information concerning the values of the kinetic parameters of the reaction controlling the velocity of a reverse combustion front is derived from the interpretation of laboratory experiments, using a numerical model. Introduction A great deal of laboratory and field work has been done on thermal recovery methods. The importance and limitations of these techniques have been extensively studied. However, some of the chemical and physical problems involved that needed to be elucidated were studied as part of a research program carried out by the Institut Francais du Petrole. Specific problems are created by in-situ combustion since both the possibility of combustion-front propagation and the air requirement are controlled by the extent of the exothermic oxidation reactions. Actually, the propagation velocity of a forward combustion front depends on the fuel formation and combustion, which are controlled by the kinetics of these processes; furthermore, the peak temperature is related to the heat released by oxidation and combustion reactions. Therefore, a quantitative estimation of the parameters related to the chemical aspects of the parameters related to the chemical aspects of the process is a necessary step in studying combustion process is a necessary step in studying combustion through a porous medium. General and theoretical considerations on heats of reaction and kinetics are presented and illustrated by experimental data and numerical interpretation of the results. HEAT RELEASED IN THE OXIDATION OF HYDROCARBONS DESCRIPTION OF OXIDATION REACTIONS A great number of reaction products are produced by the oxidation of hydrocarbons. By taking into account the formation of bonds between one carbon atom and oxygen, it is possible to derive the most important processes. Complete combustion, (1) 2 2 2 2H H3R C R  +  ---- O  → RR  +  CO + H O Incomplete combustion, (2) 2 2H H R C R  +  O  → RR  +  CO  +  H O Oxidation to carboxylic acid, (3) 2 2 2H OH H3 OR C H  +  --- O  → R - C  +  H O Oxidation to aldehyde, (4) H H R C Oxidation to ketone, (5) 2 2H O H R C R '  +  O  → R - C - R;  +  H O Oxidation to alcohol, (6) R' R; R C H SPEJ p. 410

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