Picric acid decomposition rate

For every 10 °C increase in temperature, the rate of decomposition is approximately doubled, but may increase as much as 50 times if the explosive is in the molten state. The rates of decomposition depend on the condition of storage and the presence of impurities which may act as catalysts. For example, nitroglycerine and nitrocellulose decompose at an accelerated rate due to autocatalysis, whereas the decomposition rate of TNT, picric acid and tetryl can be reduced by removing the impurities which are usually less stable than the explosive itself. With many of the explosives the presence of moisture increases the rate of decomposition. 

ITC heating of Iclryl increases the rate of burning of the substance. Tlus was already shown by Andreev (V ol. Ill, Fig. 6), by his later work [94J and substantiated by M. M. Jones and Jackson [87] and Japanese authors [86). Tire latter authors found for example that preheating the sample to 180 C lowers its ni.p. by 20 C and the decomposition temperature by 12 C. They also examined the samples of tetryl heated at 165°C for 3 hours by liquid chromatography, by TLC, NMR and mass specirography. They found that 2,4.6-trinitroanisol and picric acid are fonned on the thermal decomposition of tetryl at I60--200 C. 

Burning of tetryl is discussed in the monograph by Glazkova [92] and reference is given to the early work of Hinshelwood [93] who pointed out that thermal decomposition of tetryl produces picric acid which plays the part of a catalyst of the decomposition. The rate of burning of tetryl under pressure increases by addition of potassium bichromate, according to Glazkova [92]. 

A comparison of the rates of decomposition shows that the decomposition of BPO (Section 20.1.2.1) is influenced much more strongly by solvent than is the decomposition of AIBN (Table 20-2). With BPO, several irregularities are also observed. For example, is no longer constant when the range of BPO concentrations is large. The decomposition can also be accelerated by free radicals, such as triphenylmethyl, and can be retarded by inhibitors, such as quinone or picric acid. 

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