Saturated hydrocarbons oxidation

Polyisobutylene and IIR have chemical resistance expected of saturated hydrocarbons. Oxidative degradation is slow and the material may be further protected by antioxidants, for example, hindered phenols. 

The statements of the possible role of HO radicals in saturated hydrocarbon oxidation processes is proved by experimentally determined formation of sufficient amounts of hydrogen peroxide and HO radicals during oxidation of propane [27] and paraffin dehydrogenation products [28-30],... 

The low-pressure acetic acid process was developed by Monsanto in the late 1960s and proved successful with commercialization of a plant producing 140 X 10 metric tons per year in 1970 at the Texas City (TX, USA) site [21]. The development of this technology occurred after the commercial implementation by BASF of the cobalt-catalyzed high-pressure methanol carbonylation process [22]. Both carbonylation processes were developed to utilize carbon monoxide and methanol as alternative raw materials, derived from synthesis gas, to compete with the ethylene-based acetaldehyde oxidation and saturated hydrocarbon oxidation processes (cf. Sections 2.4.1 and 2.8.1.1). Once the Monsanto process was commercialized, the cobalt-catalyzed process became noncom-... 

O (nucleophilic) is necessary in allylic oxidation, and that the other species (electrophilic) are detrimental, by bringing about complete oxidation. On the other hand, some of these electrophilic species are very likely necessary for removing the first hydrogen of the saturated hydrocarbons (oxidation of butane to maleic anhydride and selective reactions of methane with oxygen). 

Figure 20. Mechanism of saturated hydrocarbon oxidation catalyzed by Ru(porp)(CO)/pyNO systems S = substrate, X = the oxygen donor (OD) such as ChpyNO, or other ligands...

The significance of the total sulfur content of kerosene varies greatly with the type of oil and the use to which it is put. Sulfur content is of great importance when the kerosene to be burned produces sulfur oxides, which are of environmental concern. The color of kerosene is of Htde significance but a product darker than usual may have resulted from contamination or aging in fact, a color darker than specified may be considered by some users as unsatisfactory. Kerosene, because of its use as a burning oil, must be free of aromatic and unsaturated hydrocarbons the desirable constituents of kerosene are saturated hydrocarbons. 

Polyisobutylene has the chemical properties of a saturated hydrocarbon. The unsaturated end groups undergo reactions typical of a hindered olefin and are used, particularly in the case of low mol wt materials, as a route to modification eg, the introduction of amine groups to produce dispersants for lubricating oils. The in-chain unsaturation in butyl mbber is attacked by atmospheric ozone, and unless protected can lead to cracking of strained vulcanizates. Oxidative degradation, which leads to chain cleavage, is slow, and the polymers are protected by antioxidants (75). 

Manganese, copper, iron, cobalt and nickel ions can all initiate oxidation. Untinned copper wire can have a catastrophic effect on natural rubber compounds with which it comes into contact. Inert fillers for use in rubbers are usually tested for traces of such metal ions, particularly copper and manganese. The problem is perhaps less serious in saturated hydrocarbon polymers but still exists. 

Peroxytnfluoroacetic acid is used tor numerous oxidations of saturated hydrocarbons and aromatic compounds It oxidizes alkanes, alkanols, and carboxylic acids with formation of hydroxylation products [29] Oxidation of cyclohexane with peroxytnfluoroacetic acid proceeds at room temperature and leads to cyclohexyl trifluoroacetate in 75% yield, 1-octanol under similar conditions gives a mixture of isomeric octanediols in 59% yield, and palmitic acid gives a mixture of hydroxypalmitic acids in 70% yield [29]... 

Aeckersberg F, F Bak, F Widdel (1991) Anaerobic oxidation of saturated hydrocarbons to COj by a new type of sulfate-reducing bacterium. Arch Microbiol 156 5-14. 

This last comment is a warning on the potential risk that dinitrogen tetroxide presents as a reagent vis- i-vis the particular alcohol-acid. The paragraph on hydrocarbons confirms this. This oxide has even caused accidents with saturated hydrocarbons (these can be due to impurities). In any case, there is every chance that oxide will activate the methyl groups of this compound. 

The nature of dangerous reactions involving organic chemicals depends on the saturated, unsaturated or aromatic structures of a particular compound. Saturated hydrocarbons are hardly reactive, especially when they are linear. Branched or cyclic hydrocarbons (especially polycyclic condensed ones) are more reactive, in particular as with oxidation reactions. With ethylenic or acetylenic unsaturated compounds, the products are endothermic . 

The CH4/CI2 mixture is explosive if it contains more than 20% of chlorine. If mercury oxide is present, the reaction is very violent. The accidents mentioned below deal with saturated hydrocarbons. 

Interaction of chlorine with methane is explosive at ambient temperature over yellow mercury oxide [1], and mixtures containing above 20 vol% of chlorine are explosive [2], Mixtures of acetylene and chlorine may explode on initiation by sunlight, other UV source, or high temperatures, sometimes very violently [3], Mixtures with ethylene explode on initiation by sunlight, etc., or over mercury, mercury oxide or silver oxide at ambient temperature, or over lead oxide at 100°C [1,4], Interaction with ethane over activated carbon at 350°C has caused explosions, but added carbon dioxide reduces the risk [5], Accidental introduction of gasoline into a cylinder of liquid chlorine caused a slow exothermic reaction which accelerated to detonation. This effect was verified [6], Injection of liquid chlorine into a naphtha-sodium hydroxide mixture (to generate hypochlorite in situ) caused a violent explosion. Several other incidents involving violent reactions of saturated hydrocarbons with chlorine were noted [7],... 

In this behavior, sulfur resembles iodine, which reacts in an analogous way to form polyiodides. Sulfur will also remove hydrogen from saturated hydrocarbons to produce H2S with the formation of carbon-carbon double bonds. Sulfur dissolves in hot concentrated nitric acid as a result of being oxidized as shown in this reaction ... 

The accumulation of hydroperoxide accelerates the ester oxidation. As in hydrocarbon oxidation, this acceleration is the result of hydroperoxide decomposition into free radicals. The most probable is the bimolecular reaction of hydroperoxide with the weakest C—H bond of saturated ester (see Chapter 4). 

Nitroxyl radicals (AmO ) are known to react rapidly with alkyl radicals and efficiently retard the radical polymerization of hydrocarbons [7]. At the same time, only aromatic nitroxyls are capable of reacting with alkylperoxyl radicals [10,39] and in this case the chain termination in the oxidation of saturated hydrocarbons occurs stoichiometrically. However, in the processes of oxidation of alcohols, alkenes, and primary and secondary aliphatic amines in which the chain reaction involves the HOT, >C(0H)02 , and >C(NHR)02 radicals, possessing the... 

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