Designing energetic covalent organic frameworks for stabilizing high-energy compounds

As an emerging high-energy compound,3-nitro-1,2,4-triazol-5-one(NTO)is used in military explosives and rocket propellants.However,the strong acidic corrosion of NTO,and the high sensitivity and poor thermostability of its salts,severely restrict their practical applications.Therefore,a novel strategy to design and construct energetic covalent organic frameworks(COFs)is proposed in this study.We have successfully prepared a two-dimensional crystalline energetic COF(named ECOF-1)assembled from triaminoguanidine salt,in which NTO anions are trapped in the porous framework via the ionic interaction and hydrogen bonds.The results show that ECOF-1 exhibits superior thermal stability than energetic salt of NTO.It also exhibits insensitivity and excellent heat of detonation of 7,971.71 kJ·kg−1.ECOF-1 greatly inhibits the corrosiveness of NTO.In prospect,energetic COFs are promising as a functional platform to design high-energy and insensitive energetic materials.

High energy and insensitive explosives based on energetic porous aromatic frameworks

The design and synthesis of energetic materials with a compatibility of high energy and insensitivity have always been the research fronts in military and civilian fields.Considering excellent performances of porous organic frameworks and the lack of research in the field of energetic materials,in this study,a new concept named energetic porous aromatic frameworks(EPAFs)is proposed.The strategy of coating high energy explosives such as 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane(CL-20)and 1,3,5,7-tetranitro-1,3,5,7-tetrazocane(HMX)in the EPAFs by wet-infiltration method has successfully realized the assembly of target energetic composite materials.The results show that the 75 wt.%CL-20@EPAF-1 possesses the safer impact sensitivity of 31.4 J than that of CL-20(4.0 J).Notably,for 75 wt.%CL-20@EPAF-1,in addition to the superior detonation performances of the detonation velocity(8,761 m·s^(-1))and detonation pressure(31.27 GPa),the synergistic effect of the nitrogen-rich EPAFs and the nitramines high energy explosives results in a higher heat of detonation that surpasses the most of pristine high explosives and reported novel energetic materials.In prospect,energetic porous aromatic frameworks could be a promising and inspiring strategy to build high energy insensitive energetic materials.