An aldehyde-group-containing energetic ZIF with unprecedented “negative” catalytic properties for seven different energetic materials

Abstract

Energetic materials possessing high energy content, exceptional heat resistance, and insensitivity have long been recognized as a significant and prominent subject of academic debate. In this study, the necessity for high-energy explosives in both military and civilian domains prompted the introduction of the concept of an “energetic negative-burning rate catalyst” in heat-resistant and insensitive energetic materials. Therefore, a typical and effective catalyst (ZIF-90) was discovered. ZIF-90, which can be easily synthesized and features a large specific surface area and regular pore structure, contributes to molecular-scale changes in the pyrolysis process of energetic materials. Additionally, the presence of surface aldehyde groups facilitates the partial absorption of heat, thereby collectively contributing to the augmentation of pyrolysis peak temperatures for seven distinct energetic materials (RDX, HMX, CL-20, LLM-105, LLM-126, AlH3, and DAP-4). Specifically, the pyrolysis peak temperatures were elevated by 6.6 ​°C, 1.7 ​°C, 1.6 ​°C, 6.4 ​°C, 1.4 ​°C, 13.1 ​°C, and 7.0 ​°C, respectively. Moreover, the highly stable ZIF-90, functioning as an intrinsically insensitive Energetic Metal-Organic Framework (EMOF), not only effectively mitigates the sensitivity of energetic materials but also ensures minimal energy loss. Notably, the incorporation of a mere 5 ​wt% of ZIF-90 resulted in a significant enhancement of over one-fold in the heat resistance of LLM-105-based explosive cylinders, thereby validating the practical applicability of ZIF-90 in energetic materials. Moreover, the efficacy of ZIF-90 in solid propellant formulations was corroborated through flame experiments conducted on solid propellants. The development of such a pragmatic and universally applicable energetic negative-burning rate catalyst presents a promising strategy for the future advancement of high-performance, heat-resistant, and insensitive energetic materials.