Preparation and Properties of NC/TATB/Bu‐NENA/TMETN Low Sensitive Gun Propellants

Abstract Safety improvements in the field of energetic materials promoted the development of insensitive gun propellants. A low sensitive gun propellant was prepared by traditional extrusion using nitrocellulose (NC) as a binder, 1,3,5‐triamino‐2,4,6‐trinitrobenzene (TATB) as insensitive solid energetic filler, N‐butyl‐N‐nitramine (Bu‐NENA) as insensitive plasticizer, trimethylolethane trinitrate (TMETN) as co‐plasticizer, and graphite as thermal conductive filler. The density of gun propellants obtained was 1.611 g ⋅ cm−3 which was almost equaled to the theoretical density of 1.615 g ⋅ cm−3. The gun propellants exhibited excellent mechanical properties, especially cryogenic mechanical property, with the impact strength of 12.4 kJ ⋅ m−2 and the compressive strength of 157.1 MPa at −40 °C. The closed bomb test was conducted to investigate the energy and combustion performance. The results showed that the gun propellants had stable and regular combustion properties at a pressure up to 600 MPa. The burning rate pressure index n was about 1, and the impetus f and covolume α were 1045 kJ ⋅ kg−1 and 0.9764 cm3 ⋅ g−1 respectively. The vulnerabilities of the prepared gun propellants were evaluated by bullet impact, fragment impacts, sympathetic detonation, fast cook‐off, and slow cook‐off tests. The results showed that no response that was more severe than burning in test bombs was observed in bullet impact, fast cook‐off, and slow cook‐off tests under the given conditions. Moreover, a partially combustion reaction occurred in the fragment impact test with no obvious burning reaction in the sympathetic detonation test. It demonstrates that the prepared gun propellants possess good low vulnerability characteristics.