Investigation of the combustion and stability of nitrocellulose-based propellants containing TNEF and SMX

Abstract. The feasibility of high-energy formulations, able to sustain high performances while using significant amounts of burning rate modifiers was investigated for spherical propellants. The latter are traditionally used for small-calibre applications, and this work investigates the use of HEDOs (high-energy dense oxidisers) to provide enough oxygen to maximise the combustion potential of the nitrocellulose matrix and achieve higher performances. This may be a potential route to broaden the applicability of spherical propellants to medium-calibre applications. Tris(2,2,2-trinitroethoxy)methane, also known as TNEF or trinitroethyl formate[1], and SMX (1,4-dinitrato-2,3-dinitro-2,3-bis(nitratomethylene) butane[2]) were synthesised and characterised, on a hundred-gram scale. Spherical and extruded propellants were prepared, containing increasing amounts of TNEF or SMX, and using traditional and green stabilisers [3, 4]. The energetic materials were investigated in terms of stability, compatibility and burning rate. The results obtained for the synthesis of the additive, the formulation and production of the propellants and their stability are presented in this poster. A brief kinetic study made by means of HFC (Heat Flow Calorimetry) and using the AKTS Thermokinetics software [5][4] is provided, comparing the behaviour of conventional double-base propellants and spherical propellants containing TNEF and SMX. References: [1] D. E. Dosch, K. Andrade, T. M. Klapötke, B. Krumm. An Optimized & Scaled‐Up Synthetic Procedure for Trinitroethyl Formate TNEF. Propellants, Explosives, Pyrotechnics 2021, 46, 895-898. [2] D. E. Chavez, M. A. Hiskey, D. L. Naud, D. Parrish. Synthesis of an energetic nitrate ester. Angew Chem Int Ed Engl 2008, 47, 8307-8309. 10.1002/anie.200803648 [3] A. Dejeaifve, R. Dobson. Tocopherol stabilisers for nitrocellulose-based propellants. PCT/EP2016/053948 2016, European Patent Office, The Hague. [4] A. Dejeaifve, A. Sarbach, B. Roduit, P. Folly, R. Dobson. Making Progress Towards »Green« Propellants – Part II. Propellants, Explosives, Pyrotechnics 2020, 45, 1185-1193. 10.1002/prep.202000059 [5] AKTS. https://www.akts.com/.