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The contradiction between flammability and packing density is the technical bottleneck for combustible smoke agent. Herein, polyurethane (PU) foams with flammability and resilience were prepared with polyol and isocyanate as raw materials by chemical foaming method, then compounded with metal powders, polytetrafluoroethylene (PTFE), phthalic annychide (PA), etc. in a certain proportion and pressed into pyrotechnic grain to obtain eco-friendly combustion aerosols with compact density of about 1.15 g/cm3. The resulting combustion smoke agent combined the advantages of PU foam and pyrotechnic with easy ignition, large smoke production, long duration and low environmental pollution. The transmittance of aerosols for 532 nm and 1064 nm lasers was close to 0, and the EMI SE reached up to 65 dB and 35 dB in GPS band and X band, respectively. In addition, the resulting pyrotechnic grains exhibited good mechanical strength and elasticity for sample 1:25, with a compressive strength of 22 MPa and an elastic modulus of 195 MPa. The resulting combustion smoke agent is expected to play a potential role in the field of electromagnetic damage and protection. [ABSTRACT FROM AUTHOR]

In the present study, thermal hazards of TNT and DNAN used as the molten binder in TKX-50-based meltcast explosives were comparatively studied through accelerating rate calorimeter (ARC) and Cook-off experiments. Two kinds of ARC operation modes were performed to investigate the thermal safety performance under adiabatic conditions (HWS mode) and constant heating (CHR mode). The obtained results demonstrated that at both heating modes, DNAN/TKX-50 outperformed TNT/TKX-50 from the thermal safety point of view. However, the sensitivity to heat of the samples was reverse because of the different heating modes. In addition, the results of thermal hazard assessment obtained from the cookoff experiment complied with ARC analysis which indicated the molten binder TNT replaced by DNAN would reduce the hazard of the TKX-50 melt cast explosive. Furthermore, the results of cook-off experiments also showed that DNAN/TKX-50 outperformed TNT/TKX-50 from the aspect of thermal stability, which was consistent with the result of CHR mode because of the similar heating process. [ABSTRACT FROM AUTHOR]

3-nitro-1,2,4-triazol-5-one (NTO) is the main component of insensitive munitions (IM) formulation because of its outstanding insensitive properties. In this paper, a series of NTO/HMX-based composite explosives were prepared and characterized. The study focuses on the effect of NTO on the performance of the formulations, especially the safety performance. The results revealed that the mechanical sensitivity of formulations was associated with NTO content, as well as the thermal conductivity, specific heat capacity and Arrhenius parameters. Then, the high amount of NTO using in formulation was proved to be helpful for NTO/HMX-based formulation to exhibit good thermal safety. Besides, by accelerating rate calorimeter (ARC) and a modified cook-off equipment, the pressure and pressure rise rate were proved as the important indicator for judging the thermal safety performance in confined spaces. Finally, the numerical simulation was used as a credible method for predicting the respond temperature of cook-off experiment. [ABSTRACT FROM AUTHOR]