Research On Modified Single Base Propellant Containing RDX With Low Temperature

The temperature sensitivity coefficient of gun charge had great influence on interior ballistic performance of gun. Propellants with low burning rate temperature coefficient can reduce the temperature sensitivity coefficient of gun. By adding ultra-fine RDX to single-base propellant, modified single-propellant which can adjust the combustion area to different temperature was got. This special single-base propellant was prepared by solvent method. The physical and chemical properties and combustion performance of the modified single base propellant were tested and compared.Results of the scanning electron microscopy demonstrated that the structure of modified single base propellant was heterogeneous and the bond between RDX and NC was not strong at room temperature. Results of three-dimensional experiment demonstrated that the modified single-propellant with the same RDX content had less cracks at high temperature than at low temperature. In the same condition, with more RDX, the modified single base propellant had more cracks. Because the modified single-base propellant had different interior structure at different temperature, the propellant obtained different combustion area at different temperature and had low temperature coefficient.Results of mechanical experiments suggested that anti-compression strength, tensile strength and impact strength decreased with the RDX content increasing at the same temperature and the mechanical property of the same modified single-base propellant decreased with the temperature reducing.Results of the dates of DSC experiment which can be used to analysis of propellant thermal decomposition performance showed that the activation energy of the modified single base propellant were less than single base propellant, especially propellant contenting5%RDX. So, the burning rate of modified single base propellant changed little with the temperature that is, the modified single base propellant had low temperature coefficient. What’s more, propellant contenting5%RDX had lower temperature coefficient.Results of closed bomb tests demonstrated that burning rate pressure exponent of modified single base propellant with5%RDX was lower than that of single base propellant, and the burning rate temperature coefficient of modified single base propellant with5%,10%,15%RDX was lower than that of single base propellant. These results showed that modified single base propellant had lower temperature coefficient in some extent and the propellant with5%RDX had lowest temperature coefficient. The relative steepness of modified single-base propellant containing5%,10%RDX was lower, whatever at high temperature or low temperature or normal temperature, so the propellant with5%,10%RDX can combust safely.Considering all aspects of mechanical property, thermal decomposition and combustion performance, the modified single base propellant with5%RDX had lower temperature coefficient and better mechanical property and can combust safely.