Nitrogen-rich skeleton reassembled ECOFs as energetic materials with low sensitivities and good corrosion resistance

Corrosion between energetic materials and metal containers can accelerate material aging and failure, significantly affecting the safety, reliability, and lifespan of ammunition systems. To address this challenge, we propose the construction of energetic covalent organic frameworks (ECOFs) as a promising solution. We introduce a straightforward method for synthesizing nitrogen-rich ECOFs. The synthesized ECOFs were characterized through powder X-ray diffraction (PXRD), solid-state nuclear magnetic resonance (ssNMR), and Fourier-transform infrared spectroscopy (FTIR). These frameworks exhibit remarkable thermal stability, with decomposition temperatures above 285 °C. Notably, they display low sensitivity to non-explosive stimuli, as evidenced by impact sensitivity over 60 J and friction sensitivity over 360 N. The anti-rust properties of the ECOFs were further evaluated using Tafel curve analysis, highlighting their exceptional resistance to metal corrosion. Particularly, ECOF-3, synthesized from triaminoguanidine nitrate and 5-nitro-1,3-benzenedicarboxaldehyde, stands out for its superior steel corrosion resistance. These ECOFs have potential applications as high-energy, anti-corrosion coatings materials.