Electrical Energy Injection and Ignition Mechanism of Hydroxylamine Nitrate-Based Electrically Controlled Solid Propellant

The electrical energy injection and ignition mechanisms of HAN-ECSP (hydroxylamine nitrate-based electrically controlled solid propellant) are critical technology limiting its engineering application. The mechanisms are investigated through the characterization and testing of various samples in this paper. The mixed cross-linking of HAN and PVA (polyvinyl alcohol) is a prerequisite for the injection of electrical energy into the propellant. directly bind to PVA, facilitating its dissolution, whereas connect via hydrogen bonding. Boric acid strengthens the cross-linking effect of PVA, resulting in a decrease in the conductivity of the propellant and an increase of the energy injection voltage, making ignition of the propellant more difficult. When the boric acid content is 0%, the propellant conductivity is 2.9 S/m, and at 120 V, the propellant can generate a 1 A electrolysis current. When the boric acid content is 2%, the propellant conductivity is 2.0 S/m, 400 V can only generate a 0.3 A current. At high voltages, the main reaction at the anode is the electrolysis of , while the main reaction at the cathode is the electrolysis of .Due to the higher electrolysis voltage of , electrical energy is concentrated at the anode interface. The propellant needs to reach a temperature above 400 °C to ignite. High boric acid content leads to the concentration of electrical energy at the cathode interface, causing the propellant to burn out and fail at the cathode. Adding water to the anode surface further intensifies this problem.