Enhancement strategy of mechanical property by constructing of energetic RDX@CNFs composites in propellants, and investigation on its combustion and sensitivity behavior

In the domain of energetic materials (EMs), the high-energy and high-strength propellants are always what are the scientists pursuing to satisfy the great demands of fast development and replacement for artillery. Recently, the emerging of cellulose nanofibers (CNFs) has attracted great interests since its extraordinary performances like biocompatibility, carbon-neutral nature, tailorable surface chemistry, and unprecedented mechanical properties. Inspired by the fascinating high strengthen of CNFs, this study prepared a kind of energetic hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX)@CNFs composites firstly, and then applied them in conventional double-based gun propellant (GP) to study its energy, combustion and mechanical, and sensitivity performances. The results of the mechanical properties demonstrated that the impact strength of RDX@CNFs-GP with different content of CNFs was improved by 34.9-104.7%, 7.1-39.4%, 14.4-51.2% under the condition of low, room and high temperature, the compression strength was improved by 8.6-49.5%, 4.3-45.9%, 6.2-47.8%, while the tensile strength was improved by 0.6-21.2%, 7.0-19.5%, 9.0-26.0%, respectively. Moreover, the impact and electrostatic spark sensitivities have also been increased by 21.8% and 61.8% in terms of the maximum value and exert favorable desensitization effect compared with blank sample. Notably, the propellant added with CNFs could burn steadily without anomalous combustion behavior, and the energy level of the RDX@CNFs-2.0%-GP (1180.70 J/g) maintain relative close value to that of RDX@CNFs-0%-GP (1184.84 J/g) with regard to the gunpowder impetus. Lastly, the enhancement mechanism of the CNFs in GP was discussed and proposal. Hence, this present work could potentially provide fundamental theory and data support for the development of CNFs in high-strength and high energy propellants.