The Correlation between Chemical Stability and Binder Network Structure in NEPE Propellant

Abstract

AbstractThe correlation between chemical stability and binder network structure is investigated to explore the aging mechanism of NEPE propellant. Through 70 °C aging storage experiments, propellant samples of different aging time periods are obtained every 7 days. The relative contents of MNA, NG, and BTTN are measured as the characteristic parameters of chemical stability. Gel fractions and cross‐linking densities are detected as the characteristic parameters of binder network structure properties. Experimental results show that: (1) MNA content decreases slowly from 0 to 35 days and has a quadratic function relationship with time, then quickly drops linearly from 36 to 77 days, and the contents of NG and BTTN decrease as cubic function relationships with time. When aging to 56 days, the chemical stability of propellant becomes worse; (2) the gel fraction and cross‐linking density increase at first, then decrease as time lapses, the decline rate of gel fraction and cross‐linking density increase after 67 days and 63 days, respectively; and (3) the aging of structural performance lags behind the aging of chemical stability. The network structure parameters decrease logarithmically with MNA content, and the contents of nitrate esters have quadratic function relationships with gel fraction and cubic function relationships with cross‐linking density. In summary, excellent chemical stability plays a positive role in maintaining good network structure in the process of propellant storage.