Jesse Moran

Decompositions of Urea and Guanidine Nitrates

The decompositions of urea nitrate (UN) and guanidine nitrate (GN) are determined with isothermal heating followed by quantification of both remaining nitrate and remaining base. Activation energies determined for UN were 158 and 131 kJ/mol with the preexponential factors being 1.39 × 1012 s−1 and 2.66 × 109 s−1 for nitrate and urea, respectively. These pairs of Arrhenius constants predict decomposition rates less than a factor of two apart. For GN the activation energies were 199 and 191 kJ/mol with the preexponential factors being 1.94 × 1015 s−1 and 3.20 × 1014 s−1 for nitrate and guanidine, respectively. These pairs of Arrhenius constants predict identical decomposition rates. Literature values for ammonium nitrate decomposition indicate that it should decompose somewhat slower than UN and faster than GN. DSC also indicates this ordering but suggested that UN is substantially less stable than was observed in the isothermal experiments. Decomposition products, both gaseous and condensed, are reported for UN and GN, and decomposition routes are suggested. Experimental results indicate that is generated during the decomposition mechanism. This mechanism appears to differ from that of the analogous nitro derivatives.

Training dogs to detect Triacetone Triperoxide (TATP)

Dogs have been used successfully to detect drugs and conventional high explosives. The world-wide rise in terrorist activities has placed emphasis on the detection of non-conventional explosive materials such as the multi-functional peroxides, triacetone triperoxide (TATP) and hexamethylene triperoxide diamine (HMTD). This study demonstrates that dogs can detect both solid TATP and TATP adsorbed to cotton balls. An effective procedure to train dogs to detect TATP using cotton balls permeated with TATP vapor is provided. The various trials showed that dogs were capable of detecting as little as 200 μg of TATP adsorbed to a one gram cotton ball under a variety of circumstances. However, since TATP vaporizes rapidly at room temperature, significant depletion of TATP from cotton balls can occur in as little as 20 minutes, hampering the ability of the dogs to detect it. The TATP depleted cotton ball can be refreshed by returning it to a sealed container with TATP residue for about 20 minutes. A presumed decomposition product of TATP, acetone, cannot be used in place of TATP to train dogs.

Decomposition of Azo- and Hydrazo-Linked Bis Triazines

In a search for novel energetic materials, azo-linked bis triazines were pursued. Herein the thermal decomposition of 14 simple triazines and 16 hydrazo- or azo-linked bis triazines were studied using mass spectrometry, permanent gas evolution, and differential scanning calorimetry. At temperatures far above the melting/decomposition point, decomposition was complete. Lower temperatures provided insight into the stability of the functional groups pendant to the triazine rings. Decomposition gases were identified by chromatography; they indicated little degradation of the triazine rings. The s-triazine ring system appears very stable, resisting decomposition up to 550°C while its substituents undergo relatively isolated chemistry.

Efficiency of perchlorate consumption in road flares, propellants and explosives

When an explosive detonates or a propellant or flare burns, consumption of the energetic filler should be complete but rarely is, especially in the presence of large amounts of non-combustible materials. Herein we examine three types of perchlorate-containing devices to estimate their potential as sources of contamination in their normal mode of functioning. Road flares, rocket propellants and ammonium nitrate (AN) emulsion explosives are potentially significant anthropogenic sources of perchlorate contamination. This laboratory evaluated perchlorate residue from burning of flares and propellants as well as detonations of ammonium nitrate emulsion explosives. Residual perchlorate in commercial products ranged from 0.094mg perchlorate per gram material (flares) to 0.012mg perchlorate per gram material (AN emulsion explosives). The rocket propellant formulations, prepared in this laboratory, generated 0.014mg of perchlorate residue per gram of material.