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.

To study the mechanical properties of highly filled hydroxy-terminated polybutadiene (HTPB) propellant with 90 wt% solid fillers, the stress–strain curves of the propellant under different temperatures (−50 to 70 °C) and strain rates (0.000476 to 0.119048 s⁻¹) were obtained by uniaxial tensile test. Moreover, to obtain the glass transition temperature and understand the effect of low temperatures on the mechanical properties of the propellant, DMA experiments were carried out. On this basis, the mechanical response laws of the propellant were analyzed, and the master curves of mechanical properties were established. Furthermore, the fracture features of the propellant under typical loading conditions were obtained by SEM, and the corresponding failure mechanisms were analyzed. The results show that the maximum strength decreases with increasing temperature, while the maximum elongation increases with increasing temperature at the same strain rate. The maximum tensile strength increases with increasing strain rate, while the maximum elongation decreases with increasing strain rate at the same temperature. The maximum tensile strength is lowest with a value of 0.35 MPa when the temperature is 343.15 K and the strain rate is 0.000476 s⁻¹, at which time the maximum elongation reaches the highest with a value of 44%. In terms of failure mechanisms, the propellant shows no particle fracture, and the failure modes of the propellant are mainly matrix tearing and dewetting.

To address the issues of slow curing rate, post-curing reactions, and suboptimal mechanical properties in the carboxyl-terminated polybutadiene (CTPB)/epoxy resin (EP) binder system used for solid propellants, this study optimized the curing system by introducing 593 aliphatic amine compounds containing primary and secondary amine groups as a cure accelerator. It is found that the incorporation of the cure accelerator improved the fracture strength and elongation at break of the CTPB/EP binder system. With the addition of 0.3 wt.% cure accelerator, the tensile fracture strength increased to 0.37 MPa, while the elongation at break reached 655%. Moreover, augmenting the quantity of cure accelerator can substantially elevate the crosslink density and gel fraction of the binder system. When the addition reaches 0.3 wt.%, the crosslink density is 4.3 × 10⁻⁴ mol/cm³. Further studies showed that 593 cure accelerator reduced the activation energy of the curing reaction of the CTPB/EP binder system, with higher levels of cure accelerator resulting in lower activation energy. This study established a preparation methodology for a CTPB/EP binder system with high elongation and tensile strength. These findings provide a solid scientific foundation for the application of CTPB-based binder systems in solid propellants.