Initial oxidation temperature

GPI Glass Packaging Institute IOT initial oxidation temperature... 

Increased oxidizing temperature during the first oxidation-reduction cycle appears to reduce the degree of pulverization. These data are shown in Tests 20, 5, 7, 8, 9, and 10. The amount of material greater than 297 microns appears to pass through a minimum between 400 and 450°C. However, the amount of material 297/a to >37/x. size and 37p. to >20 sizes increases markedly while the amount of material less than 20 microns decreases markedly as the initial oxidation temperature is increased. 

High pressure (60—350 MPa) free-radical polymerization using oxygen, peroxide, or other strong oxidizers as initiators at temperatures of up to 350°C to produce low density polyethylene (LDPE), a highly branched polymer, with densities from 0.91 to 0.94 g/cm. ... 

Alkylaziridines can be stereospecifically deaminated to alkenes by reaction with m-chioroperbenzoic acid (70AG(E)374). The reaction and work-up are carried out in the dark to avoid isomerization of the cw-alkene, and the mechanism is thought to involve an initial oxidation to an amine oxide followed by a concerted elimination. Aziridine oxides have been generated by treating aziridines with ozone at low temperatures (71JA4082). Two... 

For delignified boards, a constant or at higher temperatures an increasing rate of heat release with time is interpreted as a radical initiated oxidation, maybe catalysed by some of the intermediate oxidation products - but retarded by radical scavengers formed in the degradation of lignin. 

Aldehydes do not co-oxidize alkanes due to a huge difference in the reactivity of these two classes of organic compounds. Alkanes are almost inert to oxidation at room temperature and can be treated as inert solvents toward oxidized aldehydes [35]. Olefins and alkylaromatic hydrocarbons are co-oxidized with aldehydes. The addition of alkylaromatic hydrocarbon (R2H) to benzaldehyde (R1H) retards the rate of the initiated oxidation [36-39]. The rate of co-oxidation obeys the equation [37] ... 

Compelling evidence suggesting that the breakdown of hydroperoxyl groups is not related to polymer destruction, at least in the initial period of oxidation at temperatures below 400 K, comes from experiments on the initiated oxidation of polymers. It was found that the destruction of polymers develops in parallel with their oxidation from the very onset of the process, but not after a delay related to the accumulation of a sufficient amount of hydroperoxyl groups [129]. These experiments also demonstrated that it is free macroradicals that undergo destruction. Oxidation of polymers gives rise to alkyl, alkoxyl, and peroxyl macroradicals. Which radicals undergo destruction can be decided based on the kinetics of initiated destructive oxidation. 

Stannyl radicals are usually generated by homolytic substitution at hydrogen in a tin hydride, or at tin in a distannane, or, conjugatively, at the y-carbon atom in an allylstannane.453 The initiator is commonly AIBN at ca. 80 °C. In the presence of a trace of air, organoboranes are oxidized by a radical chain mechanism, and triethylborane is now commonly used as an initiator at temperatures down to —78°C,519 and it can be used in aqueous solution.520 9-Borabicyclo[3.3.1]nonane (9-BBN) has similarly been used to initiate the reaction of tin hydrides at 0 and —78°C,521 and diethylzinc works in the same way.522... 

The sustained decomposition of a substance without introduction of any other apparent ignition source besides thermal energy and without air or other oxidants present. Autodecomposition is the result of a thermal self-decomposition reaction for given initial conditions (temperature, pressure, volume) at which the rate of heat evolution exceeds the rate of heat loss from the reacting system, thus resulting in an increasing reaction temperature and reaction rate. 

These materials are very easily autoxidised and often have a low autoignition temperature. It is reported that many of the less volatile liquid aldehydes will eventually inflame if left exposed to air on an absorbent surface. The mechanism is undoubtedly similar to that giving rise to easy ignition in the air-oxidation of acetaldehyde and propionaldehyde initial formation of a peroxy-acid which catalyses the further oxidation[l]. Autoignition temperatures of lower aldehydes are much reduced by pressure, but appear to depend little on oxygen content. The effect is worst in the presence of free liquid, in which initial oxidation appears to occur, possibly catalysed by iron, followed by ignition of the vapour phase [2], An acetaldehyde/rust mix exploded at room temperature on increasing the air pressure to 7 bar. 

The dependence of the PL intensity and peak position on oxidation temperature for three different PS samples is shown in Fig. 7.20. Oxidation at 600°C destroys the PL, while the initial PL intensity is restored or even increased after oxidation at 900°C. This effect can be understood as a quenching of PL because of a high density of defects generated during the desorption of hydrogen from the internal surface of PS. Electron spin resonance (ESR) investigations show a defect with an isotropic resonance (g= 2.0055) in densities close to 101 cm for oxidation at 600°C [Pel, Me9]. This corresponds to one defect per crystallite, if the crystallite diameter is assumed to be about 5 nm in diameter. 

FIGURE 3.7 Species mass fraction profiles for a constant temperature reaction of moist CO oxidation. Initial conditions temperature = 1100K, pressure = latm, Xco = 0.002, XH0 = 0.01, Xq2 = 0.028, and the balance N2 where X are the initial mole fractions. 

A thermal oxidation of 2,3-dimethyl-2-butene, 16, occurs in NaY when the temperature of the oxygen-loaded zeolite in raised above — 20°C [35], Similar thermally initiated oxidations were not observed for the less electron rich tram-or cix-2-butene. Remarkably, pinacolone was conclusively identified as one of the products of the reaction of 16, This ketone is not a product of the photochemical Frei oxidation (vide supra) and underscores the very different character of these two reactions and the complexity of the oxygen/16 potential energy surface, A rationale for the different behavior could lie in the different electronic states of the reactive oxygen-CT complex in the thermal and photochemical reactions. Irradiation could produce an excited triplet-state CT complex ( [16 O2] ) and/ or ion pair ( [16 02 ] ) with different accessible reaction channels than those available to a vibrationally excited ground-state triplet complex ( [16 "02]) and/... 

The conventional preparative routes to anionic, neutral, or cationic complexes of indium start with the metal, which is dissolved in a suitable mineral acid to give a solution from which hydrated salts can be obtained by evaporation. These hydrates react with a variety of neutral or anionic ligands in nonaqueous solvents, and a wide range of indium(III) complexes have been prepared in this manner.1 Alternatively, the direct high-temperature oxidation of the metal by halogens yields the anhydrous trihalides, which are again convenient starting materials in synthetic work. In the former case, the initial oxidation of the metal is followed by isolation, solution reaction, precipitation, and recrystallization. 

Table I. Effect of Initial Reaction Temperature on Oxidation of Dihydroanthracene to Anthraquinone0...

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