Fabrication and Characterization of Viton@FOX-7@Al Spherical Composite with Improved Thermal Decomposition Property and Safety Performance

To achieve a uniform distribution of the components and a better performance of aluminized composite explosives, Viton (dipolymers of hexafluoropropylene and vinylidene fluoride) @ FOX-7 (1,1-diamino-2,2-dinitroethylene) @Al microspheres and FOX-7/Viton@Al were synthesized by spray-drying strategy contrastively. Viton@FOX-7@Al owned porous and loose morphology and good sphericity with a retained crystal phase of FOX-7 and aluminum. The 23.56% fluorine content on Viton@FOX-7@Al surface indicated that Viton was completely coated on the surface of the particles. Nanosized aluminum (nAl) in Viton@FOX-7@Al had a certain catalytic activity on the thermal decomposition process of FOX-7 resulting in a depressed exothermic peak temperature and reduced apparent activation energy relative to nAl in FOX-7/Viton@Al. Because of the specific structure and the synergies between each individual component, Viton@FOX-7@Al showed reduced impact sensitivity and friction sensitivity than those of FOX-7/Viton@Al. In brief, Viton@FOX-7@Al with multilevel coating structure possessed comparatively low thermal decomposition energy requirement and improved safety performance.

Oat-hull cellulose nitrates for explosive compositions

Cellulose nitrates similar in basic properties to high-viscosity lacquer-grade Colloxyline were synthesized by esterification of pulp with mixed acid. The pulp was isolated from the easily renewable domestic feedstock - oat hulls - the agro-industrial waste. The cellulose nitrate test samples were comparatively evaluated. Infrared and 13C NMR spectroscopies confirmed the chemical structures were identical. It was established by differentiated scanning calorimetry and ampule chromatography that the samples had a high chemical purity. The cellulose nitrates were found to have satisfactory impact and friction sensitivities of 50 mm and 1200 kgf/cm2 and exhibit a good chemical compatibility and a high chemical stability when blended with plasticizers. The findings suggest that it is advisable to use oat-hull cellulose nitrates as the component of composite explosives.