Nano-sized aluminum powders (n-Al) are usually added to high energy explosives and propellants o promote their detonation and combustion performance. From the perspective of thermal safety, this work focused on the thermal decomposition and explosion properties of CL-20 in the absence and presence of 30 wt% n-Al (CL-20/n-Al). The results of DSC experiments showed that the activation energy ( $E_{\alpha }$) of thermal decomposition of CL-20 slightly decreased upon addition of n-Al, implying that n-Al exhibited a certain degree of catalytic effect on the thermal decomposition process of CL-20, but the catalytic activity is quite low. By nonlinear multivariate regression method, the kinetic model for the thermal decomposition of CL-20 and CL-20/n-Al was determined as n-th order reaction with autocatalysis, and both the reaction order (n) and autocatalytic kinetic rate constant ( $k_{cat}$) of CL-20 were found to be lower than those of CL-20/n-Al, indicating that the complexity of the decomposition reaction system and autocatalytic ability of CL-20 during thermal decomposition increased upon addition of n-Al. By the deflagration point tests, the Five-Second explosion temperature ( $T_b$) of CL-20 and CL-20/n-Al was determined to be 277.7°C and 282.3°C, respectively. Moreover, the activation energy ( $E_b$) of thermal explosion of CL-20 and CL-20/n-Al were calculated as 159.98 kJ mol⁻¹ and 100.7 kJ mol⁻¹, respectively. From the more than one-third reduction of $E_b$ value, it can be concluded that the thermal sensitivity of CL-20 explosive could be remarkably decreased by adding n-Al, especially under the low-temperature condition.

Mainly the purpose of this research is to increase the oxidation efficiency of boron powder as well as to accelerate the decomposition of AP by carrying out the trials of several metals with boron-based and AP-based propellants. B/Mg, B/Al, B/Ni, B/Fe and B/Mo composites are prepared by employing ball milling method. The thermal analysis of doped boron powder with Fe and Mo shows the better activity and reaction performance. Then, the solid propellant (SP) is kneaded within proposed proportions of B/Metal composites, HTPB and AP. The B/Metal composites have improved the combustion performance of SP in air, notably in closed bomb and these had an obvious accelerating effect on the thermal decomposition of SP, especially B/Fe. The burning rates of SP/B/Fe in air and closed bomb are 60.4 and 139% faster than that of SP, respectively. Furthermore, B/Fe changed the decomposition process of AP and dropped in the peak temperature due to Fe-promoting effect. The multiple oxidation states enable Fe to be an attractive candidate as a dopant in propellants, which exhibits superior activity in the oxidation of B and decomposition of AP.

To improve the combustion stability and ignition performance of thermite, B/NC/CuO micro particles were prepared from boron (B), nano copper oxide (CuO), and nitrocellulose (NC) as an energetic binder through the electrospray technique. The burning rate dependency on boron content, ambient temperature, and pressure was estimated by compressing B/NC/CuO micro particles into columns. Scanning electron microscopy results show that the sizes of these particles mostly lie in the range of 3–4 μm. The particles are ignitable and burn consistently with minor variations in the conditions: B content (8.3–17%), ambient temperature (−50–55 °C), and ambient pressure (0.02–0.1 MPa). The optimum formula was observed for micro particles with 11 wt% B content. Compared with the ball milling sample, the standard deviation of the burning rate of the electrosprayed sample was reduced by 32%. Combustion is barely affected by ambient pressure. Between −50 °C to 55 °C, the burning rate of B/NC/CuO increases by 14.16% from an initial rate of 13.35 mm⋅s⁻¹. In addition, the laser ignition energy required for B/NC/CuO microparticles was also reduced from 70 to 45 mJ.

The effects of flame retardant silica (SiO₂) and magnesium hydroxide (Mg(OH)₂) on the thermal decomposition process of polyimide (PI) are discussed in this paper. Firstly, the decomposition process of PI in a nitrogen and oxygen atmosphere was studied by thermogravimetric analysis and differential scanning calorimetry methods, and the kinetic parameters were calculated by the nonlinear fitting method. In an inert atmosphere, PI decomposition consists of a three-step endothermic reaction, whereas in an oxygen atmosphere, PI decomposition consists of two steps, in which the first step does not change, and the second step changes to a violent exothermic peak. The effects of 3 wt % SiO₂ (SPI) and 3 wt % Mg(OH)₂ (MPI) on the degradation kinetics of PI are discussed. The results show that under an oxygen atmosphere, SiO₂ and Mg(OH)₂ hydroxide mainly delayed the second-step oxidation exothermic peak temperature of PI by 5 °C. In summary, the first step of the PI degradation is not affected by oxygen, and the flame retardant mainly acts in the second step, which can delay the oxidation heat release. In addition, the addition of SiO₂ could prevent PI from aging whereas Mg(OH)₂ has barely effect on the aging of PI.