Yujiao Wang

Preparation and Safety of Well-Dispersed RDX Particles Coated with Cured HTPB

HTPB/IPDI (hydroxyl terminated polybutadiene & Isophorone diisocyanate) and TNT (2,4,6-trinitrotoluene) were successively coated on RDX (hexogen) particles by solvent evaporation and aqueous slurry melting, respectively. When HTPB coated on RDX particles cured completely, TNT was removed by solvent dissolution and the well-dispersed RDX particles coated with cured HTPB were obtained successfully. SEM (scanning electron microscopy), TEM (transmission electron microscopy), XPS (X-ray photoelectron spectrometry), and laser granularity measurement were employed to characterize the coated samples, and the mechanical sensitivity and thermal stability were measured and analyzed. Results show that TNT on the outer layer effectively hinders the adhesion among the particles resulting from the curing of inner layer (i.e., HTPB and IPDI). The final coating particles disperse well and their mechanical sensitivity decreases significantly. When the covering amount of HTPB is 2 wt.%, drop height (H50) of RDX increases from 37.2 to 66.5 cm and explosion probability (P) decreases from 92 to 16%. Compared with that of uncoated samples, the activation energy and self-ignition temperature of coated samples do not vary.

Applications of Nanocatalysts in Solid Rocket Propellants

Abstract Catalysts are widely used in solid rocket propellants to improve their properties and ballistic efficiency. Various researchers have shown that the performance of catalysts is enhanced with the catalysts particle size reduction. Nanocatalysts, including metal nanoparticles (Ni, Cu, Al), metallic oxide nanoparticles (Fe 2 O 3 , CuO, Co 2 O 3 ), and hydrogen-storage nanoparticles (LiH, MgH 2 , Mg 2 NiH 4 , Mg 2 CuH 3 ), were prepared and investigated. The catalytic impact of these nanocatalysts on the thermal decomposition of ammonium perchlorate (AP) and AP/HTPB propellant and the impact of nanocatalysts on the combustion performance of AP/HTPB propellant were investigated.

Production and characterization of nanometer explosives

Nanometer explosives, such as RDX, HMX and CL-20, have been produced in large scale. The SEM observations show that the prepared particles are semi-spherical at the size about 60 nm having the narrow size distributions. The nanometer explosives have the same purity and crystal form with the micron-sized explosives. Compared with the micron-sized explosives, the friction sensitivity, impact sensitivity and shock sensitivity of nanometer explosives are obviously by 20%, 40% and 50% respectively. These desirable results are very encouraging and may lead to various potential applications of nanometer explosives in PBXs and CMDB propellants.