Safe Fabrication, Thermal Decomposition Kinetics, and Mechanism of Nanoenergetic Composite NBC/CL-20.

Abstract

Benefiting from the sol–gel technology and vacuum freeze-drying technology, a novel nanoenergetic composite material nitrated bacterial cellulose (NBC)/CL-20 (hexanitrohexaazaisowurtzitane) has been fabricated. The thermal decomposition kinetic and mechanism have been studied by thermogravimetric analysis–differential scanning calorimetry (TG–DSC) under nonisothermal conditions in a nitrogen atmosphere at multiple heating rates; the process and mechanism of thermal decomposition of NBC/CL-201:1 have also been probed by TG–DSC–IR. The kinetic and thermodynamic parameters, such as activation energy (Ea), per-exponent factor (ln AK), rate constant (k), activation heat (ΔH⧧), activation free energy (ΔG⧧), and activation entropy (ΔS⧧) are calculated. The results indicate that NBC/CL-20 presents much lower activation energy than both of raw NBC and raw NC, and NBC/CL-201:1 exhibits superior thermal performance of heat release and Ea. Moreover, there the existence mechanism has also been probed between NBC and CL-20 during the process of thermal decomposition. The structure and composition have been characterized by a series of characterization methods and indicate that CL-20 has been embedded homogenously in the NBC gel matrix with a prominent porous cross-linked network structure. The impact and friction sensitivities have also been decreased. The whole process effectively avoids high temperatures, and thus ensures operational safety.