The physical and chemical nature of sensitization centers left from hot spots caused in triaminotrinitrobenzene by shock or impact

Abstract

Samples of triaminotrinitrobenzene (TATB), a well-known explosive, were taken to the brink of ignition by either underwater shock or impact and were investigated for the generation of hot spots. SEM was used for detecting, locating, and measuring the size of the hot spot remnants. These were found to be tiny ragged holes in the explosive with a fine deposit of debris near them. By use of XPS, a specially surface-sensitive technique, it was found that the debris consisted of furoxan and furazan derivatives of TATB produced from its decomposition. The furoxans are far more sensitive than TATB and constitute sensitization centers where reaction can easily restart during handling of the explosive. The hot spot sites were of micron size for the impacted samples and an order of magnitude smaller for the underwater-shocked samples.

Liquid state thermochemical decomposition of neat 1,3,5,5-tetranitrohexahydropyrimidine (DNNC) and its DNNC-d2, DNNC-d4, DNNC-d6 structural isotopomers: Mechanistic entrance into the DNNC molecule

“…In every case, the same mechanistic rate-controlling bond rupture found in the ambient pressure decomposition process for each compound, proved to be a significant ratecontrolling mechanistic feature observed in rapid deflagration [8,14], high-pressure combustion [14][15][16], and thermal explosion events [3,14]. Furthermore, it is detected as being a significant contributing mechanistic feature in impact or shock explosive initiation sensitivity [12,[17][18][19][20][21][22][23]. Identification of the pathway directing initial bond rupture, of the subsequent rate-controlling bond rupture, and of the resultant product composition formed during the thermochemical decomposition processes are critical for obtaining energetic compounds with improved thermochemical and initiation sensitivity properties.…”

“…Thirdly, sub-initiation impact and shock studies, where the charred inner surfaces of hot spots caused by a rapid thermochemical decomposition process, also reveal condensed phase intermediate condensed phase products with intact ring structures for TNT [22], TATB [21], and RDX [14,20]. In the case of structurally related RDX, sub-initiation by impact displays trigger linkage or first reaction N O bond rupture to form the analogous trinitroso intermediate compound [45].…”

Kinetics and mechanisms of thermal decomposition of nitroaromatic explosives

“…Furazan and furoxan formation ocours with TATB that has been thermally decomposed and sbaritecally shocked or impacted ( References 162,[192][193][194]. …”

“…(Reference 75) proposed that characteristics of the C-NO 2 bond are the main This is the only initiation reaction that TNB, MATS, DATS, and TATB could have in common to account for the smoothly increasing trend of impact sensitivity ( Table 1). The observation of furazan and furoxan compounds in heated, impacted and shocked samples of TATB ( References 162,[192][193][194] is understandable from the fact that the temperature during heat-up and cool-down emphasizes the lower Ea cyclization channel. The shocked and impacted samples did not explode and, therefore, did not reach the temperature range where C-NO 2 homolysis could dominate.…”

Moisture Desorption Rates from TATB Formulations: Experiments and Kinetic Models

“…Currently, there are two plausible mechanisms under debate: (1) the inter/intramolecular H-atom transfer [1][2][3][4][5][6] and (2) the C-NO 2 bond homolysis or rearrangement (which includes the nitro-nitrite isomerization mechanisms). 2,5,[7][8][9][10][11] Numerous studies have investigated the validity of these two mechanisms and careful research has validated each of these mechanisms. Such a scenario indicates that the chemical mechanism(s) of TATB are complex and depend heavily on the conditions (e.g.…”