Improved corrosion resistance and thermal stability of insensitive NTO explosives by MXene modification in the presence of non-covalent bonds

Abstract

Strong corrosiveness to metals is the main factor restricting the widespread application of the insensitive explosive 3-nitro-1,2,4-triazole-5-one (NTO). Herein, MXene rich in active functional groups was obtained by selective etching of Ti₃AlC₂, and fine-grained MXene/NTO composites with rod-like morphology were prepared by recrystallization. The incorporation of MXene not only significantly reduced the particle size of explosives from 25 to 8 μm, but also weakened the impact sensitivity from 32% to 20% and friction sensitivity from 28% to 16%. Meanwhile, the enhanced corrosion resistance and thermal stability of the resulting NTO/MXene composites benefited from the introduction of MXene. The corrosiveness of NTO aqueous solution to metals was due to the easy ionization of hydrogen in the molecular structure, MXene with active groups combined with hydrogen atoms in NTO by non-covalent bonds, resulting in difficult hydrogen ionization and corrosion resistance without changing the chemical properties of explosives. The good thermal conductivity of MXene endowed NTO with improved thermal stability and promoted the crystallization of NTO as a nucleating agent. These insensitive explosives with good comprehensive properties would be the mainstay of the upgrading of weapons and equipment.