Enhanced Thermal Decomposition and Laser Ignition Properties of Nanostructured NC/Al/RDX Composite Fibers Fabricated by Electrospinning

Abstract

Nano Al has always been the research hotspot in the field of energetic materials because of its high energy density and combustion temperature, and has been considered as a fuel to enhance the energy release of various propulsive systems. In this work, nanocomposite fibers were fabricated by electrospinning technology, in which nano Al and recrystallized RDX particles were integrated with NC fibers. The morphology and chemical components of NC/Al, NC/RDX, and NC/Al/RDX composite fibers were characterized by XRD, FT-IR, SEM, TEM and BET. The agglomeration of nano Al particles in fibers is significantly inhibited, and the recrystallized RDX and nano Al particles are uniformly dispersed in NC fibers, resulting in the rough surfaces of the composite fibers. The thermal analysis shows that nano NC fibers have lower thermal decomposition temperature (202.1 ℃) and apparent activation energy (149.32 kJ mol-1) than raw NC (208.2 ℃ and 218.5 kJ mol-1), and NC/Al/RDX exhibits improved thermal decomposition properties compared with NC/RDX and NC/Al. The laser ignition experiments suggest that the uniformly dispersed nano Al particles could obviously promote the combustion and shorten ignition delay time. However, RDX may delay ignition due to its high decomposition temperature, but can significantly enhance the combustion properties of NC/Al/RDX fibers. Among the all samples, the NC/Al/RDX (1:1:0.2) exhibits shortest ignition delay time and most violent combustion flames, which can be attributed to the fibrous structure and the enhanced heat and mass transfer between the components.