Scientists from the ZIOC have developed a novel family of highly energetic components for rocket propellants based on polycyclic cage multi-nitramine structures

Energetic compounds represent a special category of diverse materials having a high amount of stored chemical energy that can be released by combustion processes. These materials are ingredients of energetic compositions extremely important application area for which is rocketry and aerospace technologies.“Strained” cage nitramines are an excellent backbone for the design of a new generation of high-energy materials. The representative of this type of compound, 2,4,6,8,10,12-hexanitrohexaazaisowurtzitane(CL-20), is one of the most promising energetic materials, but it also has disadvantages, the main of which is high sensitivity to mechanical stimuli.

Researchers of the Laboratory of Organic Synthesis of the ZIOC have elaborated methods for effectively tuning of CL-20 properties at the molecular level by extension its nitramine structure. As a result, a new family of high-energy materials were synthesized, combining covalently bonded the pentanitrohexaazaisowurtzitane cage and an open-chain nitramine unit. The studies performed have shown that the incorporation of nitramine substituents enhances the resistance of the polynitro cage backbone to external influences. The most remarkable is that using a bis-methylene-N-nitramide bridge, for the first time, two structural units of CL-20 have been assembled into a uniform alkylnitramine system. The obtained materials exhibit high density, heat resistance and enthalpy of formation. Moreover, they are the most insensitive among energetic hexaazaisowurtzitane derivatives known, are several times safer against impact/friction than CL-20 and are noticeably less sensitive than widely used cyclic nitramines HMX and RDX. The combination of admirable properties makes these materials promising for use in high-energy condensed systems. The target compounds of the research have detonation characteristics at the level of the most powerful standard explosives and are highly effective energetic components for metal-free rocket propellants, providing, at moderate contents, significantly higher specific impulse values than similar formulations based on CL-20.

Source:

Vladimir V. Parakhin, Galina V. Pokhvisneva, Tatyana V. Ternikova, Sergei V. Nikitin, Gennady A. Smirnov, Tat'yana S. Kon′kova, David B. Lempert, Alla N. Pivkina Energetic alkylnitramines-functionalized pentanitrohexaazaisowurtzitanes: towards advanced less sensitive CL-20 analogues J. Mater. Chem. A, 2022, advance article. DOI: 10.1039/D1TA08866A.