Effect of Nitroguanidine on the Combustion Performance of NEPE Propellant

Abstract: In order to meet the urgent demand of tactical missiles for low-cost and high safety nitrate ester plasticized poly-ether (NEPE) propellants, NEPE propellants containing different mass fractions of nitroguanidine (NQ) were prepared by par-tially replacing RDX with NQ. The influence of NQ introduction on the combustion characteristics of the propellant were stud-ied. The influence of NQ on the thermal decomposition performance of propellant was tested by TGA-FTIR. Its mechanical properties and sensitivity were tested. The results indicate that the addition of NQ increased the burning rate of the propellant at low pressure and reduced the pressure index over the pressure range of 7-11 MPa significantly (such as the pressure index of propellant sample 4 is 0.13), exhibiting near platform combustion characteristics. NQ alters the thermal decomposition pathway of AP, accelerating its high-temperature decomposition and inhibiting its low-temperature decomposition. NQ and RDX exhibit significant interactions in the liquid phase, with thermal weight loss peaks advanced by 31.67 C and 14 C. re-spectively. The introduction of NQ significantly improved the tensile strength of the propellant. When the NQ content increased from 0 to 9%, the σm increased from 0.34 MPa to 0.94 MPa; NQ enhances the energy dissipation through mechanisms such as fracture, resulting in a 56% reduction in impact sensitivity. Formula of sample 3 meets the performance requirements of tactical weapon equipment with low pressure index, low sensitivity, and excellent mechanical properties.