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The simultaneous incorporation of N-oxide and nitramine is a significant approach for improving the oxygen balance, density and detonation performance of energetic materials. Herein, an intramolecular hydrogen-bond block was stabilized in novel s-triazine energetic materials. Meanwhile, as the first instance of successful N-oxidation in the s-triazine backbone, the as-synthesized energetic compounds exhibited multipurpose applications. Compound 4 showed detonation performance comparable to that of FOX-12 but more insensitive and thermally stable (IS ＞ 80 J, Td: 275 °C). Compound 5 presented excellent physical and detonation properties similar to RDX, including high densities (up to 1.86 g cm−3), high energetic performances (calculated detonation velocity: 8762 m s−1) and low mechanical sensitivities (IS = 40 J) superior to those of RDX, demonstrating promise as a novel insensitive highly energetic material. [ABSTRACT FROM AUTHOR]

Dicarbohydrazide bis[3-(5-nitroimino-1,2,4-triazole)] (DCBNT) was firstly synthesized by ion exchange and salt formation reaction. A combination of single-crystal X-ray diffraction (SXRD), FTIR, 1H NMR, 13C NMR, and elemental analysis was utilized to analyze the structure and composition of DCBNT. DCBNT exhibits a high detonation velocity of 9234.87 m s−1 and a detonation pressure of 31.73 GPa as calculated by EXPLO5 v6.02 program. In addition, the sensitivities (impact sensitivity ＞40 J, H50 = 90 cm, and friction sensitivity = 216 N) and thermal stability (＞230 °C) of DCBNT were investigated. Moreover, we measured the solubility of DCBNT in 12 common solvents by a polythermal method system which demonstrates its poor solubility in common organic solvents and water. These excellent physicochemical properties make DCBNT an environmentally friendly, low-sensitivity and high-energy explosive. [ABSTRACT FROM AUTHOR]

Modifying the properties of energetic materials is important not only for gaining insight into the relationship between structures and properties but also for multiple applications. A new family of energetic compounds, polynitroimidazoles featuring trinitromethyl, nitromethyl and methyl acetate moieties at the nitrogen position of heterocyclic rings were synthesized. The high‐energy oxidizers 2‐nitro and 4‐nitro‐1‐(trinitromethyl)‐1H‐imidazoles were obtained by nitration of 1‐acetonylpolynitroimidazoles in fuming HNO3 and concentrated H2SO4. 4,5‐Dinitro‐1‐(nitromethyl)‐1H‐imidazole and 4,5‐dinitro‐1‐(acetate methyl)‐1H‐imidazole were afforded by using 68 % HNO3 and concentrated H2SO4 through controllable synthesis. All the intermediates and the target compounds were confirmed by X‐ray diffraction. It is noteworthy that one of the N‐trinitromethyl nitroimidazole derivatives showed high density (ρ: 1.88 g cm−3), attractive positive oxygen balance (Ω: +18.3 %) and good detonation performance (D: 9003 m s−1) exceeding those of ADN, while N‐nitromethyl derivative behaved higher thermal stability and lower sensitivity in contrast to those of NG. N‐acetate methyl derivative gave an interesting melt‐castable property (Tm.p.: 86 oC, Td: 224 oC), acceptable detonation performance as well as low sensitivity towards impact and friction (IS>40 J, FS>360 N), making it a competitive replacement for DNAN. These chemical and physical properties indicate that these novel materials show promising energetic performance towards future applications. [ABSTRACT FROM AUTHOR]

• Four novel HEPMs are prepared via the facile method. • HEPMs can be ignited without any additives under the combustion tests. • HEPMs have been first proposed for metal-free catalytic performance of AP. Energetic polymeric materials play vital roles in energetic materials fields to improve the comprehensive performances of rocket propellants and PBXs. Herein, four N-di/trinitrobenzene based heat-resistance energetic polymeric materials were synthesized via two facile approaches and fully characterized using FTIR, NMR, SEM and XRD. The combustion properties of energetic polymers were tested and recorded on a high-speed camera, physicochemical and energetic properties were also investigated. The results show that as-synthesized energetic polymers not only exhibit excellent thermal stabilities (the highest exothermic decomposition temperature of 336.7 °C) superior to those of GAP, poly(GLYN), triaminoguanidine-glyoxal polymer (TAGP) and graphene oxide (GO), but also produce great detonation and compatibility performance. In addition, the energetic polymer samples can be directly ignited without any additives. Worth noting that, we reported the thermal decomposition catalysis of AP by non-metallic energetic polymers as the first example, suggesting they can be potentially developed into metal-free catalysts replacing heavy metal-based energetic coordination polymers (ECPs) or energetic metal-organic frameworks (EMOFs). In summary, as-prepared energetic polymeric materials represent great application potential in solid rocket propellants and PBXs due to their promising catalytic effect, excellent chemical and physical performances. [ABSTRACT FROM AUTHOR]

Novel nitrogen-rich hybrid via pyrazol-traizole and its ionic salts were designed and developed as thermally stable and insensitive next-generation green energetic materials. • Novel pyrazol-triazole nitrogen rich hybrids are prepared via facile methods. • Their physical performance and crystal packing with various characterizations are performed. • These new materials have high densities, low mechanical sensitivity, and excellent thermal stability. • This study provides a new concept of constructing nitrogen-rich compounds for green energetic materials. The barrier in the development of energetic material is the material design and performance improvement based on it. Currently, creative design and preparation of novel nitrogen-rich compounds are significant for new generation of green energetic materials. At the present work, organic heterocyclic hybrid pyrazol-triazole was constructed, synthesized and applied as building blocks in the development of versatile thermally stable high-energy materials. All derivatives were fully characterized by vibrational infrared spectroscopy (IR), multinuclear NMR (1H, 13C) spectroscopy, elemental analysis, differential scanning calorimetry (DSC), impact and friction-sensitivity test. Additionally, the structures of 4 – 8 and 10 – 13 were further confirmed by single-crystal X-ray diffraction and their crystal packing characteristics were thoroughly analyzed. Compound 2 not only enchanced physical properties of its ionic derivatives obviously, but also showed good detonation performance (D: 9075 m s−1) exceeding that of RDX, excellent insensitivity (IS > 80 J, FS > 360 N) comparable to that of TATB and superior thermal stability (331 °C) to that of HNS. Its ionic salts (compounds 4 – 14) also exhibit reasonable properties, such as good experimental densities (1.75–2.10 g cm−3), high thermal stability (174289 °C), good safety properties, excellent detionation performance (D v: 7745–8952 m s−1, P : 23.830.6 GPa), suggesting this new pyrazol-triazole hybrid is beneficial for improving their physical performance. This work is helpful for accelerating the discovery of insensitive, thermostable and high-energy green energetic materials. [ABSTRACT FROM AUTHOR]