Electrospun Nano-boron–Ammonium Dinitramide Core–sheath Nanofibers

Abstract

The nano-boron powder (n-B) exhibits remarkable efficacy as a combustion catalyst, making it a prime candidate for use in solid propellant metal burners. Nevertheless, throughout the storage phase, the surface of n-B powder is prone to oxidation and substantial agglomeration, resulting in challenges with ignition and incomplete energy dissipation when utilizing boron powder. The synthesis of nano-boron/nitrocellulose/ammonium dinitramide@fluorine rubber (n-B/NC/ADN@F₂₆₀₂) is accomplished via the coaxial electrospinning technique, with n-B uniformly dispersed within the core–shell fiber. The n-B is evenly distributed within the core–shell fiber, and as a result of F₂₆₀₂ encapsulation, the moisture absorption of n-B/NC/ADN@F₂₆₀₂ has decreased from 191.6 to 10.1%. In the course of combustion, the fibrous composite of n-B/NC/ADN@F₂₆₀₂ undergoes an escalation in the rates of energy output and energy release, owing to the constraints imposed by external F₂₆₀₂. The n-B/NC/ADN@F₂₆₀₂ demonstrates a 1.3-fold rise in peak pressure and a 1.15-fold increase in maximum pressure rise rate compared to n-B/NC/ADN. Furthermore, the maximum flame temperature is elevated by 150.5 ℃, and the combustion heat is augmented by approximately 8.7%. The findings of the energy performance assessment reveal that the mean molecular weight (MC) of the combustion byproduct of n-B/NC/ADN@F₂₆₀₂ stands at 27.6 g·mol⁻¹, markedly surpassing that of n-B/NC/ADN. The aforementioned findings exemplify that coaxial electrospinning is an exceedingly efficacious technique for enhancing nanostructures, thereby amplifying the reactivity of energetic particles and offering novel insights into their application in energetic materials.