The nitrate ester plasticized polyether (NEPE) propellants were accelerated aged at 65 70, and 75 degrees C, respectively The dynamic mechanical properties of NEPE propellants were determined with the dynamic mechanical analysis method The strength limit of NEPE propellants was tested by the uniaxial tension test The relaxed modulus and strength limit both decreased By calculating the structural integrity of NEPE grain the effects of modulus changes on the structure integrity were analyzed The results provide a reference for the life prediction of solid rocket motor containing an NEPE propellant