Thermal decomposition of energetic materials 53. Kinetics and mechanism of thermolysis of hexanitrohexazaisowurtzitane

✍ Scribed by D.G. Patil; T.B. Brill

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 422 KB
• Volume: 87
• Category: Article
• ISSN: 0010-2180
• DOI: 10.1016/0010-2180(91)90164-7

✦ Synopsis

The kinetics of thermal decomposition of hexanitrohexazaisowurtzitane (HNIW) were measured by the isothermal weight loss (TGA) and absorbance changes in the FTIR spectrum at 1 atm. Below 204"C, the initial 50% of decomposition follows the power rate expression k(T)(l -cO n with n = 1,2. The activation energy is 36.3 + 0.6 kcal/mol and log A of 13.6 s-l for n = 1. The data do not fit an autocatalytic decomposition model. Thermolysis in the 250"-400"C range was studied by the fast-heat-and-hold/FTIR technique. N--NO 2 homolysis dominates the decomposition rate in the lower temperature range and NO 2 is the major gas product. Several later stage decomposition reactions of HNlW are proposed in light of the nature of the gas products, their concentration ratios as a function of temperaturo, and information on the residue. The NO/NO 2 ratio shows that oxidation of the residue by NO 2 becomes increasing important at higher temperatures.