Synthetic and thermal studies of four insensitive energetic materials based on oxidation of the melamine structure

Oxidation of nitrogen-rich aromatic heterocycles has a significant impact on the development of energetic materials. 2,4,6-Triamino-1,3,5-triazine-1,3-dioxide (MDO) is a promising insensitive energetic backbone obtained from melamine under strong oxidation conditions with impressive thermal behaviors and detonation performances. In this paper, MDO was prepared with improved yields of 85% and its thermal behavior, non-isothermal decomposition kinetics and gas products were investigated in detail. The corresponding decomposition mechanism was also deduced by applying the TG-DSC-FTIR-MS technique for the first time. The decomposition temperature of MDO reaches 300 degrees C and the apparent activation energy of MDO (E) calculated by the Kissinger and Ozawa method proved to be 303.63 and 279.95 kJ mol(-1), indicating great thermal stability. Three new monoanionic energetic salts with impressively improved properties were achieved based on the basicity of MDO with yields of >80%. Their thermal decomposition temperatures proved to be higher than 230 degrees C and their densities are in the range of 1.75-1.89 g cm(-3). The calculations and experiments show that their detonation velocities (v(D): 8711-9085 m s(-1)) are comparable to or exceed those of RDX (D: 8795 m s(-1)) while the sensitivities to impact (IS: 23-27 J) and friction (FS: >240 J) are much lower.

Automated summary

The study demonstrates that MDO synthesized from melamine has excellent thermal stability and detonation speed, making it suitable for energetic materials, and three new monoanionic energetic salts have been successfully synthesized. These energetic salts exhibit high decomposition temperatures, moderate densities, comparable detonation speeds to traditional energetic materials, but lower sensitivity to impact and friction.