Polydopamine as interfacial layer regulating micron-sized boron/polytetrafluoroethylene composite to improve the combustion performance

Boron powder has high bulk calorific value and mass calorific value, and is widely used in high-energy explosives and propellants. However, in practical application, there are issues such as poor ignition performance and low combustion efficiency, which affect its energy performance. In this work, firstly, polydopamine (PDA) was used as a cladding to coat the micron-sized boron (µB) and formed µB@PDA, and then the µB@PDA was connected with polytetrafluoroethylene (PTFE) to study the effect of fluoride and PDA interfacial structure on the combustion and agglomeration of boron powder in air. Results indicate that the PDA interfacial layer thickness on the µB surface increases with the concentration of the dopamine hydrochloride mixed solution. By slowing down the rate of PTFE decomposition, the PDA coating can control the thermal reaction characteristics of µB, which in turn has a considerable impact on the flame spread and the combustion intensity. In particular, the synergy of PDA and PTFE can considerably reduce µB agglomeration during combustion.