Deceleratory period

The decomposition of silver(II) oxide in vacuum at 356—407 K exhibits a sigmoid a—time curve in which the deceleratory period predominates... 

Fig. 5.13 General form of curves relating the fraetion of C3S consumed to time in a paste. AB initial reaetion. BC induction period. CD acceleratory period. DE deceleratory period and continuing, slow reaction. Taylor et al. (T25).

Rienaecker and Werner [36] suggested that Baj(Mn04)2 is the initial decomposition product, by analogy with results for KMn04- Isothermal ar-time curves for vacuum decomposition at 413 to 463 K were sigmoid [37] following an initial (or= 0.04) burst of gas. The acceleratory process was fitted by the Prout-Tompkins equation ( , = 151 kJ mol ) and the power law with = 2. Fragmentation into thin platelets was observed. The deceleratory period could be described by the first-order equation with , = 124 kJ mol. ... 

There are no fundamental reasons that could prevent the application of these vaporization equations to cases of thermal decomposition (dissociative vaporization) of a substance, except for the requirement that the rate J must be measured under a steady-state decomposition mode, corresponding to the deceleratory period in the a—t kinetic curve. 

Thermochemistry of the induction, acceleratory, and deceleratory periods Quantitative 2.4... 

The solid kinetics of HMX is very complicated with an initial slow reaction succeeded by acceleratory and deceleratory periods. The initial slow reaction has been studied by Maksimov. He reported an activation energy of 37.9 kcal/mole and a frequency factor of 1.58 x 10 fisec. Rogers and Janney found an initial activation energy of 33.9 kcal/mole and a frequency factor of 4.8 x 10 /j,sec. ... 

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