Activation energy of thermal decomposition

According to T. Urbanski and Kruszynska [41] thallium styphnate has similar properties to those of lead styphnate. The former, however, is much more sensitive to impact than the latter. Their sensitiveness to temperature is similar contact with a metal surface heated to 351°C causes explosion after 1 sec. The activation -energy of thermal decomposition is nearly 80 kcal/mole. 

The activation energy of thermal decomposition of AP varies from 17 to 40 kcal/mol according to various authors [47]. Tlie wide discrepancy between their results was due to various conditions of the reactions, various techniques used and is a sign of the complicated nature of the reactions of the decomposition of AP. 

The work of Freeman and Anderson (62) was continued and conflnned the previous observation. Irradiation increases the number of nuclei and this affects the decomposition of the substance the decrease in tlie induction period and an increase in the rate constant [63a]. A detailed kinetic study of pre-irradiation was made by Harley and Ijevy [63b]. They also found that the activation energy of thermal decomposition of AP was unchanged by irradiation at 28.4 2.5 kcal/mol,... 

The activation energy calculated from the plots like in Fig. 4.9,66 kJ moF, is in good agreement with reference data [25] rai the activation energy of thermal decomposition of fluorinated graphite, 44—61 kJ mol. ... 

In primary and secondary nitroparaffins, hydrogen transfer reactions take place involving a 1,3-H shift [11,130]. This produces acf-forms of these compounds, which are also called nitronic acids. According to Manehs et al. [ 11 ], the existence of the aci-form of NM represents a more probable cause of lowering of activation energy of thermal decomposition of hquid NM as compared with the gas-phase thermolysis (i.e. in relation to the theories of bi-... 

Trans-esterification must also be considered when blends of PHB with other polymers are investigated, especially if they contain hydroxyl, carboxyl or other reactive moieties. A significant decrease in activation energy of thermal decomposition of PHB... 

The temperature of initiation is reported by different authors to be 110-130°C. Bircumshaw and F. M. Taylor [49] have examined the thermal decomposition of ammonium permanganate between 96 and 117°C. The activation energy of this decomposition was estimated as 27.9 kcal/mole. Within the temperature range from 70 to 80°C the energy of activation was 26.0 kcal/mole. An explosive decomposition brought about by an initiator procedes according to the reaction ... 

A tubular reactor is to be designed in such a way that it can be stopped safely. The reaction mass is thermally instable and a decomposition reaction with a high energetic potential may be triggered if heat accumulation conditions occur. The time to maximum rate under adiabatic conditions of the decomposition is 24 hours at 200 °C. The activation energy of the decomposition is 100 kj mol-1. The operating temperature of the reactor is 120 °C. Determine the maximum diameter of the reactor tubes, resulting in a stable temperature profile, in case the reactor is suddenly stopped at 120 °C. 

Distannane, Su2H6, is known to have extremely poor thermal stability leading to Sn and hydrogen . Recent measurements show that the activation energy for thermal decomposition of Su2H6 is only 5.3 0.6 kJmol but the low pre-exponential factor obtained for the rate constant suggests that the decomposition is a heterogeneous process. 

Table II. Activation Energy for Thermal Decomposition of Raw Shale and Kerogen Concentrate from Green River Oil Shale and Devonian Shale °...

It has been observed that the activation energy for thermal decomposition of ethyl nitrate is substantially reduced in the presence of lead oxide or copper surfaces. Above 200° C approximately, the thermolysis of ethyl nitrate becomes much more complex and detonation in the gas phase is common. In the range 242-260° C the reaction was found to be half-order, with an overall rate coefficient" k = 10 - exp(—46,800)/J 7 mmole. l . sec apparently the initiation step is unaltered but the subsequent radical chain mechanism affects the overall rate of decomposition. 

Maruyama and Nakai [193] showed that there is no difference in the apparent activation energy of the decomposition of DMZ (13 kJ/mol) with thermal and photo-activated MOCVD when CO2 is used as reactant gas. 

In summary, it is fair to say that there is no known error that may be applied to all the shock tube work that will account for the many reports of low activation energies for thermal decompositions. 

The scheme outlined is summarized in Figure 1, which also shows the energy level corresponding to the work function of the metal. Table I compares experimental values for the activation energies for thermal decomposition with the thermal band gaps and the energies required to excite an electron from the val-... 

Singh observed that doping lead azide with small amounts of (BiNa) (0.24 wt %) results in increased rate and decreased activation energy for thermal decomposition [101]. On this basis it could be theorized that the rate-controlling step is the transfer of an electron from the azide ion to the conduction band and that if this energy barrier is reduced, for example by adding an impurity which introduces new energy levels in the band gap, decomposition rate is enhanced. 

In spite of the observed effects of (FeNs) " and Fe " on the decomposition kinetics and absorption energy levels of lead azide, neither impurity significantly altered the activation energy for thermal decomposition. Thus, it is likely that these impurities affect the thermal decomposition rate of lead azide by altering the equilibrium concentration of reacting species (possibly N3) or sites, rather... 

Thermal decomposition of PVC is believed to be linked to the loss of plasticizers. Activation energy of thermal degradation is given by equation ... 

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