Thermal decomposition, kinetics

It is somewhat endothermic (AH°f (g) +87.5 kJ/mol, 1.0 kJ/g), the liquid may explode on pouring or sparking at 2°C, and the gas readily explodes on rapid heating or sparking [1,2], on adiabatic compression in a U-tube, or often towards the end of slow thermal decomposition. Kinetic data are summarised [3], The spontaneously explosive decomposition of the gas was studied at 42-86°C, and induction periods up to several hours were noted [4], Preparative precautions have been detailed [5],... 

A number of methods have been developed for the determination of the thermal decomposition kinetics of organic and inorganic materials. These include both isothermal and dynamic TGA method28-30 Our studies of the thermal stability of the thermoset polymer utilized isothermal evaluation of zeroth-order decomposition rate kinetics.19... 

The basic assumption inherent to heat transfer limited pyrolysis models is that heat transfer rates, rather than decomposition kinetics, control the pyrolysis rate. Consequently, thermal decomposition kinetics do not come into play, other than indirectly through specification of Tp. This approximation is often justified on the basis of high activation energies typical of condensed-phase pyrolysis reactions, i.e., the reaction rate is very small below Tj, but then increases rapidly with temperature in the vicinity of Tp owing to the Arrhenius nature, and the high activation energy, of the pyrolysis reaction. 

The relative ease or difficulty of incineration has been estimated on the basis of the heat of combustion, thermal decomposition kinetics, susceptibility to radical attack, autoignition temperature, correlations of other properties, and destruction efficiency measurements made in laboratory combustion tests. Laboratory studies have indicated that no single ranking procedure is appropriate for all incinerator conditions. In fact, a compound that can be incinerated easily in one system may be the most difficult to remove from another incinerator due to differences in the complex coupling of chemistry and fluid mechanics between the two systems. 

Thermal decomposition kinetics of complexes have been studied by thermogravimetry and differential thermal analysis in order to understand the thermal stability and the mechanism... 

In the case of Gd-dimethylglyoxime thiourea complex, four molecules of lattice water are lost at 130°C followed by an endothermic peak at 170°C and a complete loss of dimethylglyoxime at 210°C. The residue was analyzed and found to be Gd(thiourea)3Cl3. Normally it is difficult to prepare the Gd thiourea complex by direct synthetic procedures. Thus this example shows that thermal decomposition kinetics is a suitable method for the synthesis of some complexes under favourable conditions. The thermal decomposition data on LnCr(tartrate) 2H2O, where Ln = La, Nd, Eu, Dy, and Er are given in Table 7.27. There are six to eight steps in the decomposition [87]. 

Thermal decomposition kinetics of LnCl3 2HMTA H20 complex, where Ln = La, Pr, Nd, HMTA = hexamethylenetetraamine and n = 8, 10, 12 show essentially the two stages in which lattice and coordinated water molecules are removed from the complex in the temperature ranges 65-80° and 135-145°C, respectively. A typical reaction scheme may be written as follows [89]. 

Miller, P. J., Block, S. and Piermani, G. J. (1991). Effects of pressure on the thermal-decomposition kinetics, chemical-reactivity and phase behavior of RDX. Combust. Flame, 83, 174-84. [283]... 

Milosavljevic I. and Suuberg E,M. (1995) Cellulose Thermal Decomposition Kinetics Global Mass Loss Kinetics. Ind. Eng. Chem. Res., 34, 1081-1091. 

Kanury, M. A., Thermal decomposition kinetics of wood pyrolysis, Combust. Flame, 18, 75, 1972. 

Thermal decomposition kinetics of poly (trirnethylene terephthalate). X-S. Xue Song Wang, X-G. Xin-Gui li, D. Deyue Yan. /Polymer degradation and stability 2000, 69 3 361-372. 

The applications of thermodynamic functions in thermal decomposition kinetics have been discussed in detail by L vov (89,90). The Hertz-Knudsen-Langmuir equation expresses the rate of monotonic evaporation,./, (which can be measured using TG) by... 

Synthesis, structure and non-thermal decomposition kinetics of scorpionates oxovanadium complexes with carboxyl acid ligand >V ° H J - 75... 

Bahta, A., R. Simonaitis, and J. Heicklen (1982). Thermal decomposition kinetics of CH302N02. J. Phys. Chem. 86, 1849-1853. 

Table 5.14. Comparison of Kinetics Methods for the Thermal Decomposition Kinetics of AIBN (183)...

The thermal decomposition kinetics of silver carbonate using the disk technique was reported by Wvdenen and Leban (59). Continuous, in siru quantitative analysis of infrared active reactants and products of the decomposition reactions was made possible by use of a heated cell. The cell was constructed of stainless steel and could be heated to 500 C with the KRS-5 cell windows maintained at room temperature by cooling water. A similar approach was used by Wendlandt (60). 

Various impurities significantly affect the thermal decomposition kinetics of metal azides the yet unfulfilled challenge is to determine by what mechanism these impurities operate. 

Williams, 1959 Gray et al., 1967 Heicklen, 1968 Howard, 1972), but no general update seems to have t peaied. However, Batt (1979) has reviewed the thermochemistry and thermal-decomposition kinetics for aikoxyl radicals and alkyl nitrites. It is the purpose of the present review to report all work through June, 1986 (and some later) on the reactions of alkoxy radicals. In addition, since aikoxyl radicals often are produced in laboratory experiments from alkyl nitrites, the photochemical and thermal decomposition of these species will also be reviewed. 

Photodynamic therapy (PDT) is a treatment that is used for the destruction of certain types of tumours, and is based on the administration of a photosensitizer that concentrates in tumour cells and, upon subsequent irradiation with visible light in the presence of oxygen, selectively destroys the cancerous cells. Wei et al. reported the thermal stability, melting temperature, enthalpy of fusion and thermal decomposition kinetics of porphyrins and their nickel complexes [205]. 

Zabihi O. Characterization and thermal decomposition kinetics of poIy(ethyIene 2,6-naphthalate) nanocomposites reinforced withtio2 nanoparticles. Polym-Plast TechnolEng 2012 51(1) 43-9. 

X.-G. Li and M.-R. Huang, Thermal decomposition kinetics of thermotr( icpoly(oxybenzoate-co-oxynaphthoate) vectra copolyester. Polymer Degradation and Stability, 64, 81 (1999). 

Thermogravimetry (or thermogravimetic analysis, TGA) is one of the oldest thermo-analytical procedures and has been used extensively in the study of polymeric systems. The technique involves monitoring the weight loss of the sample in a chosen atmosphere (usually nitrogen or air) as a function of temperature. It is a popular technique for the evaluation of the thermal decomposition kinetics of polymeric materials and hence provides information on thermal stability and shelf life. However, it is well known for its ability to provide information on the bulk composition of polymer compounds. 

A theoretical study of the thermal decomposition kinetics of ethyl fluoride 1,1-difluoroethane 1,1,1-trifluoroethane and 1,1,2,2-tetrafluoroethane has been carried out at the B3LYP/6-31-H-G, B3PW91/6-31-H-G, and MP2/6-31-h-hG levels of theory. The calculated data demonstrate that in the HF elimination reaction of the compounds studied, the polarization of the C(l)-F(3) bond is rate determining. Analysis of bond order, charges, bond indexes, and synchronicity parameters suggests that HF elimination occurs through a concerted and asynchronous four-membered cyclic TS type of mechanism. 

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