A Method for Reducing the Temperature Sensitivity of a Single-Base Propellant by Adding Ultra-Fine RDX Particles

The temperature sensitivity coefficient greatly affects the interior ballistic performance of propellant charges. Even under consistent loading conditions, variations in environmental temperature can lead to maximum chamber pressure fluctuations of 40-80 MPa, thereby compromising weapon efficiency and operational safety. In order to obtain a single-base propellant with a higher energy and lower temperature sensitivity coefficient, ultra-fine RDX particles were added into the single-base propellant. The difference in thermal expansion coefficients between RDX and the single-base propellant matrix leads to temperature-dependent microcracking. These microcracks increase the burning surface area at low temperatures, compensating for the reduced chemical reaction rate and thereby lowering the temperature sensitivity coefficient. A scanning electron microscope (SEM) was used to observe the inner structure of the single-base propellant with and without RDX particles. The thermal mechanical analysis (TMA) results, together with SEM observations, reveal that the interfaces between the propellant matrix and the RDX particles are temperature-dependent. As a result, the burning surface area of the modified single-base propellant varies with temperature, contributing to a reduced temperature sensitivity coefficient. Closed bomb tests were conducted to verify this inference, and the obtained curves and relevant quickness (RQ) values showed that the modified single-base propellant had stable burning behavior and lower temperature sensitivity. This study leverages the structural interactions between high-energy fillers and polymer matrices to provide a potential strategy for designing climate-resilient ammunition.