Functional energetic materials: Simple preparation of fluorinated materials to improve safety, preservation and energy release performance of energetic materials

Abstract

Paraffin wax (PW) coatings are widely used in the military as the most effective way to reduce the sensitivity of energetic materials, but their inert nature is not conducive to energy release. In this work, paraffin-like fluorine-containing molecules (FPW) which are highly anticipated on a large scale were synthesized by combining crystalline units with fluorine units via a simple method. Core-shell Al@FPW was prepared for further characterization. FPW exhibits better lubrication and greater density (1.14 g/cm3 vs. 0.81 g/cm3) than PW, which can provide favorable guarantees for reduced friction sensitivity and increased energy density. The similar melting temperatures and crystallization enthalpies (168 J/g vs. 201 J/g) of FPW and PW are advantageous for mitigating the temperature sensitivity of nano-Al. Furthermore, the improved hydrophobicity of Al@FPW prevents further oxidation of the active metal, thereby enhancing the preservation of nano-Al. Moreover, the reaction process of Al@FPW was characterized by DSC-Tg. Notably, the combustion pressure, pressurization rate and calorific value of Al@FPW are significantly increased compared to Al@PW. Meanwhile, the ignition delay time is reduced by 83 % and the combustion rate is increased by 330 %, which is attributed to the action of fluorine during the reaction. The exceptional performance of FPW holds great potential for replacing PW in various applications.