Solvent‐free Synthesis and Properties of Functionalized Hydrazines and Bishydrazines as Energetic Ingredients for Propulsion Applications. Issue 24 (6th November 2020) - Eymann, John
Abstract: Functionalized hydrazines and bishydrazines are interesting straightforward precursors for accessing higher nitrogenated compounds. They offer structural diversity and promising energetic properties as well, namely for propulsion applications. A novel and scalable synthesis has been developed for a new family of bishydrazines, starting from monomethylhydrazine (MMH). This solvent‐free route represents a suitable alternative to the one described in the literature. It was extended to design a new family of unsymmetrical hydrazines bearing various functional groups. A selected series of promising compounds, densified with nitrogenated groups (amino, hydrazino or azido functions), was identified as a class of plausible candidates for liquid propulsion. Indeed, the energetic interest of such hydrazines was demonstrated by computing their heats of formation and specific impulse values in bipropellant systems. This led to theoretical energetic performances comparable to that of the MMH/N2 O4 system already in use today. Abstract : A versatile synthesis based on MMH and chloroalkyl substrates has been devised leading to seventeen new functionalized hydrazines and bishydrazines. These derivatives are key‐ingredients for accessing higher polynitrogenated structures with energetic interest and tunable properties. Three of them (N/C ratio≥1) showed a low impact sensitivity, a good thermal stability and a specific impulse value similar to that of MMH bipropellant systems.