Mechanism of thermal decomposition

O. E. Wating and G. Krastins, The Kinetics and Mechanism of Thermal Decomposition of Nitroglycerin, Report 5746, NOL, White Oaks, Md., 1958. 

The data presented and discussed indicates that the mechanism of thermal decomposition of niobium oxyfluoride complex compounds is not trivial, but that some regularity can nonetheless be formulated regarding the processes, as follows ... 

It should be noted that the above classification system of technetium cluster compounds is not the only possible one. In section 4 another classification is described, which is based on thermal stability and the mechanism of thermal decomposition. Section 2.2 is concerned with the classification based on methods of synthesizing cluster compounds. The classifications based on specific properties of clusters do not at all belittle the advantages of the basic structural classification they broaden the field of application of the latter, because for a better understanding and explanation of any chemical, physico-chemical and physical properties it is necessary to deal directly or indirectly with the molecular and/or electronic structures of the clusters. 

Thermal Properties and Mechanism of Thermal Decomposition in the Solid Phase... 

As far as the mechanism of thermal decomposition is concerned, halogenide binuclear clusters with multiple M-M bonds differ considerably from other clusters in their stronger tendency to undergo disporportionation reactions to... 

The mechanism of thermal decomposition (pyrolysis) of methane has been extensively studied [90,91]. Because C-H bonds in the methane molecule are significantly stronger than C-H and C-C bonds of the products, the secondary and tertiary reactions contribute at the very early stages of the reaction, which obscure the initial processes. According to Holmen et al. [92], the overall methane thermal decomposition reaction at high temperatures can be described as a stepwise dehydrogenation as follows ... 

Malecki A., Gajerski R., Labus S., Prochowska-Klisch B., and Wojciechowski K.T. 2000. Mechanism of thermal decomposition of d-metals nitrates hydrates. J. Therm. Anal. Calorim. 60 17-23. 

It should be noted that the mechanism of thermal decomposition of acyclic nitronates was not studied in detail. It is known that cis isomers of alkyl nitronates derived from primary AN are much less stable than the analogous trans isomers (49, 237a). 

The color of the polymer can also be affected by inappropriate reaction conditions in the polymerization process, such as temperature, residence time, deposits of degraded polymer or the presence of oxygen. Degradation of polyesters and the generation of chromophores are thermally effected [29b, 29c, 39], The mechanism of thermal decomposition is based on the pyrolysis of esters and the formation of unsaturated compounds, which can then polymerize into colored products. It can be assumed that the discoloration takes place via polymerization of the vinyl ester end groups or by further reaction of AA to polyene aldehydes. 

Naono, H. Nakai, K. Sueyoshi,T. Yagi, H. (1987) Porous texture in hematite derived from goethite mechanism of thermal decomposition of goethite. J. Colloid Interface Sd. 120 439-450... 

Substituent effects on aziridine formation from N-(2-halogenoethy 1) arylsulphonamides by cyclization in basic media have been studied,425 and Hammett equation studies have also been of utility in determination of mechanisms of thermal decomposition of 3-chloro-3-aryldiazirines,426 427 the acid-catalyzed methanolysis of arylepoxides,428 and the ring expansion reactions of 2-aryl-l,l-dimethylaziridinium salts with benzaldehyde to form 5-aryl-3,3-dimethyl-2-phenyloxazolidinium salts.429... 

IR spectra measurements as well as variation of the film thickness, shrinkage, and refractive index demonstrated substantial differences in the mechanisms of thermal decomposition of films prepared from the exclusively metal alkoxide precursor and from the metal alkoxides modified by 2-ethylhexanoic acid. These differences affect the evolution of film microstructure and thus determine the different dielectric properties of the obtained films. The dielectric permittivity of the films prepared from metal alkoxide solutions was relatively low (about 100) and showed weak dependence ofthe bias field. This fact may be explained by the early formation of metal-oxide network (mostly in the... 

A detailed quantum mechanical study of the mechanism of thermal decomposition of isoxazole has been conducted since previous theoretical predictions appeared to be inconsistent with the experimental results.33 It has been concluded that the mam unimolecular decomposition is through the sequence isoxazole —> NCCH2CHO —> CH3CN + CO and that the minor products, HCN and H2CCO, probably arise via a cyclic carbene as proposed in the experimental study. 

Brill, T. B. James, K. J. Kinetics and mechanisms of thermal decomposition of nitroaromatic explosives. Chem. Rev. 1993, 93, 2667-2692. 

T.B. Brill, K.J. James, Kinetics and Mechanisms of Thermal Decomposition of Nitroaromatic Explosives, J. Phys. Chem., 93 (1993) 2667-2692. ibid Thermal Decomposition of Energetic Materials. 61 Perfidy in the Amino-2,4,6-Trinitrobenzene Series of Explosives, J. Phys. Chem. 97(34) (1993) 8752-8758. ibid. Thermal Decomposition of Energetic Materials. 62 Reconciliation of the Kinetics and Mechanisms of TNT on the Time Scale from Microseconds to Hours, J. Phys. Chem., 97(34) (1993) 8759-8763. 

Levchik, S. V., Camino, G., Luda, M. P., Costa, L., Muller, G., and Costes, B., Epoxy resins cured with aminophenymethylphosphine oxide Mechanism of thermal decomposition, Polym. Degrad. Stab., 1998, 60, 169-183. 

A. V. Rayevskii, in Mechanisms of Thermal Decomposition of Ammonium Perchlorate, Inst. Chem. Phys. Acad. Sci. USSR, Chernogolovka Branch, 1981, p. 30. 

TPD MS data have shown a dramatic difference between the mechanism of thermal decomposition of bio-active (glucose containing) and less active... 

The polymers of rubber plastics have unsaturated hydrocarbon chain structure, since they are polymerized from alkadienes. The general formula of poly(l,3-butadiene) or butadiene rubber (BR) and polyisoprene or natural rubber (NR) is drawn in Scheme 12.5, where X is hydrogen in BR and methyl group in synthetic polyisoprene or NR. The free radical mechanism of thermal decomposition starts by homolytic scission of the alkyl C-C bonds. Two primary macroradicals (4 and 5) are formed for which the rearrangement... 

K. Lenghaus, G. G. Hua Qiao and D. H. Solomon, 3,5-dimethylphenol resole resins their structure and mechanism of thermal decomposition leading to graphitisation. 

There have been a number of studies of the mechanism of thermal decomposition of HNIW (Path and Brill 1993) with a particular emphasis on the role of free radicals (Pace 1991, 1992). Ryzhkov and McBride (1996) compared the reactions at low temperature in the a and ft modifications, and found that the same cavities that contain water in the hemihydrate play an important role in differences in the solid state chemistry between the two modifications. 

The reaction behaviour for the thermal decomposition of the chlorosulphites in solution parallels that of the chloroformates very closely. Thus, Boozer and Lewis " found that when 2-pentyl chlorosulphite is thermally decomposed in dioxane solution at 62 °C both 2-chloropentane and 2-pentene are formed. The relative amounts of the substitution and elimination reactions in this instance are 51 % and 49 % respectively. With allylic chlorosulphites, substitution is accompanied by rearrangement . Boozer and Lewis - have carried out configurational checks on the mechanism of thermal decomposition in solution and deuterium isotope studies have also been made . As with the chloroformates, the experimental evidence points to transition states of a polar nature . Gas phase decompositions of chlorosulphites have been studied by Rieche and Nau-mann and Geiseler et a/. - and radical-chain mechanisms have been proposed . 

A complicating feature in the interpretation of the mechanism of thermal decomposition of diacyl peroxides is the inversion reaction... 

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