Thermal decomposition of nano Al-based energetic composites with fluorinated energetic polyurethane binders: experimental and theoretical understandings for enhanced combustion and energetic performance.

Abstract

Energetic composites composed of polymeric binders and metallic fuels are widely used in industrial and military fields, and their performance is largely dependent on the combustion process. Fluorinated energetic polymeric binders can facilitate the combustion of metallic fuels such as aluminum particles and enhance the energetic level of the energetic composites. In this report, fluorinated energetic polyurethanes (FPUs) were applied as binders for energetic composites with aluminum nanoparticles (AlNPs). The fluorinated components in the energetic binder could be a uniform dispersion inside the composites, endowing the composites with decent mechanical properties and high combustion rate. Most significantly, compared with the composites without fluorine, FPU/AlNP energetic composites not only showed a remarkably improved combustion efficiency, but also, surprisingly, a dramatic enhancement in the heat of explosion by 91.2%, despite the low content of fluorine. By analyzing the combustion products together with kinetic simulations derived from chemical reaction neural network (CRNN) modelling, a detailed mechanistic understanding of the combustion process was provided, suggesting the importance of synergistic effects brought by the fluorinated and energetic components.