Preparation of HMX@DHBA-Pb and HMX@NTO-Pb composites via in situ deposition: A way to achieve surface catalysis of HMX

In order to ameliorate the combustion properties of 1,3,5,7-tetranitro-1,3,5,7-tetrazacyclooctane (HMX) based composite modified double base (CMDB) propellants, HMX particles with many gullies are first prepared, and then 2,4-dihydroxybenzoic acid (DHBA) and 1,2,4-triazol-5-one (NTO) are used to react with lead via in situ deposition to coat HMX for preparing HMX@DHBA-Pb and HMX@NTO-Pb composites. The structures and properties of HMX@DHBA-Pb and HMX@NTO-Pb composites are characterized in detail. The characterization results show that DHBA-Pb and NTO-Pb shells are uniformly coated on HMX surfaces. The chemical structure of HMX maintains constant during in situ deposition coating process. The mechanical and thermal safeties of HMX are enhanced after coating with DHBA-Pb and NTO-Pb shells. The introduce of DHBA-Pb and NTO-Pb can catalyze the decomposition and combustion of HMX core, and the catalytic effects of in situ coating are better than that of physical mixing.