Fabrication of nitrocellulose‐based nanoenergetic composites, study on its structure, thermal decomposition kinetics, mechanism, and sensitivity

Abstract

AbstractIn order to investigate the thermal decomposition kinetics and mechanism of nitrocellulose (NC) based nitramine explosives nanocomposite energetic materials, this work prepares NC/RDX (cyclotrimethylenetrinitramine), NC/HMX (cyclotetramethylenetetranitramine), and NC/CL‐20 (hexanitrohexaazaisowurtzitane) composites by a combined sol‐gel and the freeze‐drying technology. The structure is systematically investigated and the results reveal that the explosive particles are dispersed, filled, or embedded homogenously in the gel matrix of NC, thereby restricting the crystal growth of RDX, HMX, CL‐20 particles to coarse and achieving submicron/nanometer. The thermal analysis of composites exhibits much lower peak temperature compared with raw explosive crystal, furthermore, the activation energy (Ea) of composites is also lower than that of both NC and explosives. Hence, the unique structure of NC gel matrix embedded explosives inside demonstrated different mechanism of decomposition. Concretely, the rupture of the H‐NCO = O bond in the cross‐linked structure is detected firstly, subsequently, the macromolecular chains’ scission site of gel firstly occurs at ‐C‐O‐C‐ in the ring, and then the scission of ‐NO2 (from NC or explosive crystals) bonds happened. Hence, this study may provide promising fabrication strategy and basic theory for the application of NC‐based nanocomposite energetics in high‐energy propellants and explosives.