Preparation of core-shell 5-AT@F2602 composite: Improving the compatibility of 5-aminotetrazole with nitrocellulose

The advantages of the environment-friendly products and high gas production of the azole-rich compounds have potential application prospects in the gun propellant. However, the instability of the nitrogenous multicomponent ring seriously affects its compatibility with gun propellant components. In order to improve the compatibility between 5-aminotetrazole (5-AT) and nitrocellulose (NC), a separation layer between 5-AT and NC was formed by coating fluorine rubber (type F2602) on the surface of 5-AT particles with the solvent method. The results of surface morphology showed that the 5-AT surface was completely and uniformly coated with F2602. The results of differential scanning calorimetry (DSC) and vacuum stability tester (VST) showed that the incompatibility between 5-AT and NC was greatly improved by F2602 coating, the decomposition temperature difference of NC mixed with 5-AT was reduced from 8.9°C to 3.3°C, the net reactive gas release was reduced by 55%, and the low thermal stability and storability of NC in the mixed system were improved. The kinetic analysis showed that the coating effect of F2602 reduced the chemical interaction between 5-AT and NC, and increased the decomposition temperature. Evolutionary gas analysis showed that the interaction between the reductive products of 5-AT with NO2 produced by NC was weakened after coating. The mechanism of the coating of F2602 on the 5-AT surface to improve the compatibility between 5-AT and NC was revealed. Due to the high thermal stability and excellent mechanical properties of F2602, 5-AT is tightly wrapped in F2602, which greatly weakens the interaction between 5-AT and NC. The results of this study have important guiding value for the application of nitrogen-rich energetic materials in propellants.