温度和压力载荷作用下NEPE推进剂的老化性能

To study the aging properties under loading action of induced pressure on nitrate ester plasticized polyether (NEPE) propellant, double stress accelerated life tests were performed at 75℃ and 1MPa. The effects of temperature and pressure on the combustion, energy, mechanical properties, safety characteristics of NEPE propellant were studied. The change mechanism of mechanical properties of NEPE propellant was analyzed by cross-linking density, dynamic mechanical properties and scanning electron microscopy. The results show that during accelerated aging at 75℃ and 1MPa for 30 days under the combined action of temperature and pressure, the heat of detonation of NEPE propellant is 6007-6192kJ/kg, the burning rates is 10.36-10.64mm/s, the mass fraction of stabilizer is 0.43%-0.48%, which do not change with aging time. The tensile strength decreases with the increase of aging time, and its value decreases from 0.612MPa to 0.433MPa with a change rate of 29.2% after 30 days of aging, indicating that the change of mechanical properties is the main failure model of propellant. The failure mechanism under the temperature-pressure double stress loading action is that temperature degrades the binder, destroys the nodes in cross-linking network and decomposes the solid particles to cause dehumidification, and the compressive stress strengthens the dehumidification phenomenon, which leads to the rapid decrease of mechanical strength.