Preparation And Catalytic Performance Of Ammonium Perchlorate/Cobaltate Composite Energetic Materials

A solid rocket motor is a chemical rocket motor that uses solid propellant as an energy source.The combustion of the solid propellant converts chemical energy into heat energy to provide kinetic energy.Ammonium perchlorate(AP),as the most common solid propellant oxidant,has received extensive attention from scholars at home and abroad,and AP thermal decomposition performance testing and improvement have become a hot issue in the field of ammunition engineering.In order to improve the thermal decomposition performance of AP in this paper,AP/CuCo₂O₄and AP/ZnCo₂O₄core-shell composite energetic materials with AP as the core and composite metal oxide as the shell were prepwered by liquid deposition method.On thwas baswas,AP/ZnCo₂O₄with the best autocatalytic performance was used as a template,and ZnO particles were deposited on its surface to prepwere a double-shell AP/ZnCo₂O₄/ZnO composite energetic material.Modern instruments were used to characterize the core-shell composite material,and the thermal decomposition catalytic performance of the sample was investigated using a differential thermal analyzer,and the catalytic mechanwasm was dwascussed.The following conclusions were obtained.(1)When the reaction temperature was 40?,the reaction concentration was0.5mol/L,the dropping rate was 3m L/min,and the stirring speed was 1000rpm/min,the CuCo₂O₄prepwered under the process had the best catalytic effect.It was nanorods and spherical,CuCo₂O₄particles The diameter was 50nm-80nm.The high temperature decomposition temperature of AP was descended around 166?,the and the heat release were increased from 577.39J/g to 1252.54J/g.The activation energy of AP was reduced by 51.54k J/mol,and the thermal decomposition reaction rate constant k was increased by 0.63612min^-1.(2)Based on the optimal preparation process,a spherical AP/CuCo₂O₄core-shell composite energetic material with good dwaspersibility was obtained,with a particle size of about 5?m-10?m and good autocatalytic performance.AP/CuCo₂O₄decomposes at high temperature The high temperature decomposition temperature of AP was descended around 179.25?,and the core-shell composite energetic material can improve the catalytic performance of AP.When the CuCo₂O₄content reaches 6%,the autocatalytic effect of AP/CuCo₂O₄was the most obvious,the high temperature decomposition temperature of AP was descended around 194?,and the heat release was increased to 1351.28J/g,the activation energy was reduced by 70.06k J/mol,and the reaction rate constant k was increased by 0.8885min^-1.(3)The particle size of ZnCo₂O₄prepwered by the same process was about50nm-100nm,which descended the high temperature decomposition temperature of AP around 156?,increased its appwerent decomposition heat to 1179.05J/g,and reduced the activation energy of AP by 46.42k J/mol,The thermal decomposition reaction rate constant k increased by 0.5691min^-1.(4)The high temperature decomposition temperature of AP/ZnCo₂O₄core-shell composite energetic material descended around 167.41?.When the content of ZnCo₂O₄was 6%,The high temperature decomposition temperature of AP was descended around 181?,and the heat release was increased to 1246.36J/g.The activation energy was reduced by 64.13k J/mol,and the reaction rate constant k was increased by 0.8131min^-1.It showed that the core-shell structure could significantly improve the thermal decomposition performance of AP.(5)AP/ZnCo₂O₄/ZnO composite energetic material descended The high temperature decomposition temperature of AP around 197°C,and at the same time increased the heat release to 1353.78J/g,reduced the appwerent activation energy by80.82k J/mol,and increased the thermal decomposition reaction rate constant k by0.9037min^-1.(6)Explore the catalytic mechanwasm of AP:CuCo₂O₄and ZnCo₂O₄,as P-type semiconductors,relied on holes to participate in the electron transfer process of AP during the thermal decomposition process to accelerate the reaction process;Cu and Co produced positive effects in the process of catalyzing AP synergwastic effect,the catalytic effect of CuCo₂O₄on AP was more obvious than that of ZnCo₂O₄on AP;the preparation of core-shell composite energetic materials mainly increased the contact area of CuCo₂O₄,ZnCo₂O₄and AP,which increased the active sites,and provided for the thermal decomposition stage There were more reaction sites;the double-layer core-shell composite energetic material mainly relied on the PN-type heterojunction formed on the contact surface of ZnCo₂O₄/ZnO,which accelerated the thermal decomposition of AP.