High combustion efficiency boron-based microspheres containing ICM-102 and perfluorooctanoic acid

The ignition and combustion enhancement for boron is crucial for its broad applications. In this study, several spherical boron-based aggregates have been prepared by integration of 2,4,6-triamino-5-nitropyrimidine-1,3-dioxide (ICM-102) and perfluorooctanoic acid (PFOA) to boron using polyvinyl alcohol (PVA) as a binder by centrifugal spray granulation. Their morphology, structure, and thermal properties have been characterized. The ignition and combustion performances are comparatively evaluated using TG-DSC, oxygen bomb calorimetry, and comprehensive online diagnosis. The results show that the ICM-102 and PFOA could synergistically enhance the ignition and combustion performances of boron with decreased initial oxidation temperature and over 96 % combustion efficiency. The sample with 18 % ICM-102, 10 % PFOA, and 72 % boron shows a volumetric heat value of 73.8 kJ/cm³, reduce ignition delay by 72 %, and double combustion duration compared to pure boron. It was found that the ICM-102 would react with the boron oxide layer, generating gaseous products that prevented the agglomeration. A two-step combustion mechanism could be proposed: at lower temperatures, a water vapor and hydrocarbon-rich micro-environment removes the oxide layer, whereas at higher temperatures, strong oxidizing gases sustain combustion.