Impact energy sensitivity

Centrifuging of Test material for impact/shock sensitivity and unstable material, thermal hazards shock sensitive, alternate (low energy) separation process for material could shock sensitive/unstable material result in decomposition. CCPS G-13... 

Case histories regarding reactive chemicals teach the importance of understanding the reactive properties of chemicals before working with them. The best source of data is the open literature. If data are not available, experimental testing is necessary. Data of special interest include decomposition temperatures, rate of reaction or activation energy, impact shock sensitivity, and flash point. 

The sensitiveness of tetryl to impact, as reported by several authors, may be expressed as 70-80% of the impact energy necessary to cause the explosion of picric acid. 

In reporting tests results the sample is noted as no reaction , decomposition (w/o expln) and "explosion . The drop weight in kg and the lowest height in cm (calculated as Impact energy. in kgm) are given as a measure of the sensitivity to impact, if in six tests at least one expln occurs. The sensitivity to impact of a substance is greater the smaller the impact... 

After being fused the explosive solidifies to form a mass having a density of 1.48 to 1.50 g/cm3, which needs a very strong initiation by about 30 g PETN to detonate under these conditions with a rate of estimately 6300 m/sec. Being less sensitive to mechanical shock than PETN, methyltrimethylolmethane trinitrate explodes under an impact energy more or less like that needed for tetryl. 

T. Urbanski and Magiera [85] have examined the chemical stability and explosive properties of the ester and conclude that neither the substance itself nor a solution of nitrocellulose in it are sufficiently stable for practical application. Its temperature of initiation is 150°C (whereas nitroglycol is initiated at 220°C), and it is considerably more sensitive to impact than nitroglycol. They also found that an impact energy of 0.91 kgm/cm2 is necessary to ensure a 10% probability explosion of nitroglycol, as compared with barely 0.11 kgm/cm2 for the ester. 

The sensitiveness to impact is slightly lower than that of TNT. According to Wohler and Wenzelberg [25], an impact energy of 12.1 kgm/cm2 is necessary to produce 50% explosion. Thus compared with picric acid (100) its relative sensitiveness is 109, i.e. to bring about an explosion, the impact energy has to be higher by 9% than that necessary to explode picric acid. 

Trinitro-m-xylene is more sensitive to impact than TNT. This can be explained by the presence of a large number of substituents on the benzene ring. As Wohler and Wenzelberg [14] found, it could explode at only about half the impact energy needed for the explosion of TNT. 

Other component Sensitiveness of the pure component (impact energy) kgm Sensitiveness to impact of the mixture (impact energy) kgm... 

A more precise assignment could, in principle, be based on the relative intensities of the different peaks. Although much of that information has been compiled in the literature, those earlier values are not quantitative due to the fact that experimental parameters, such as the electron impact energy, relative m/e sensitivities and the specific design of the instrument often cause marked changes in the observed peak abundances. It should be possible to measure each species with the same instrument and under the same conditions as those involved in the TPD experiments such measurements, however, have not as yet been pursued. 

The sensitiveness to impact of solid, liquid, or gelatinous explosives is tested by the fallhammer method. Samples of the explosives are subjected to the action of falling weights of different sizes. The parameter to be determined is the height of fall at which a sufficient amount of impact energy is transmitted to the sample for it to decompose or to explode. 

The impact sensitivity of 1 was tested at Julius Peter s Tester (Table 3). The test was performed after drying for 4 hours at 60 °C. At that time, the room temperature was 22 °C and relative humidity was 68 %. As the result, 50 % probability detonating impact energy of 1 was 14.6 J whereas that of HMX, class 1, was 5.4 J. It is expected that the impact sensitivity level of 1 is similar with that of Comp B. From these data, we guessed 1 might be insensitive. 

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