定应变作用下NEPE推进剂老化特性及寿命预估研究

The Aging Property and Life Prediction of NEPE Propellant under Constant Strain

为考察定应变作用下NEPE推进剂的老化特性,研究了20%定应变作用下NEPE推进剂贮存老化过程中力学性能、凝胶性能和界面性能的变化。研究结果表明:定应变作用下NEPE推进剂在贮存老化过程中最大抗拉强度降低,最大延伸率变化较小,其老化失效主要表现为强度的失效;定应变下NEPE推进剂的凝胶百分数和粘附功随老化时间的延长而降低,NEPE推进剂粘合剂基体的降解断裂和界面的"脱湿"是其主要的老化机理;定应变下NEPE推进剂的力学性能与细观性能的相关性研究表明,最大抗拉强度与凝胶百分数和粘附功存在相关关系,计算了其关系式,建立了由细观性能评估推进剂宏观力学性能的方法;选择最大抗拉强度下降30%时失效,20%定应变下NEPE推进剂的贮存寿命为8.3年。

The thermal aging properties, including the mechanical property, the gel propen＇y and interfacial property, were measured to analyze the aging characteristics of nitrate ester plasticized polyetber （NEPE） propeUant during aging process trader 20% constant strain. The results show that the maximum tensile strength is decreased while the elongation at maximal has no obvious change. The performances deterioration of NEPE propellant is the invalidation of the strength. The gel fraction and the work of adhesion are decreased along with the aging time. The main aging mechanism is the degradation of the binder matrix and inteffaeial dewetting. There is a correlation between the maximum tensile strength and the gel fraction, the adhesion work. The equation is calettlated to determine the relationship. The method is established to evaluate the maeroscopieal mechanical property by microcosmic property. Storage life of propellant under 20% constant strain is 8,3 years, while the value of deterioration of maximum tensile strength changes to 30%, it will reach the invalidation point.