Preparation, Characterization And Catalytic Performance Of Bi Based Metal Composite Oxides

The combustion process of solid propellant is one of the main factors affecting the performance of the rocket and missile. Many research workers have made tremendous efforts in order to synthesize propellants with high performance, high security and high burning rate. The combustion is a rapid oxidation process that chemicals like a series of oxidizing agent and combustion improver react quickly. Because of the complexity of the propellant formulation, different reactants may generate the same effect when reacting. In the process of studying the combustion law of solid propellant, we may encounter great obstacles. But in practical application, studies have shown that a suitable catalyst can significantly change the combustion properties of propellants. In this paper, based on the previous studies, we choose different metal composite oxides as the catalysts to research their effect on energetic materials and solid propellant.The paper selected bismuth metal composite oxides as the research object, including Anrivillins layered structure of bismuth tungstate (Bi2WO6), bismuth molybdate and burn pyrochlore type structure of bismuth stannate (Bi2Sn2O7). Different methods were used to synthesize the compounds. XRD and SEM were chosen to characterize the composite oxides. Then prepared different nano composite oxides and obtained the optimum conditions, including nano Bi2WO6:pH=10,160? and reacted at 20 h, the particle size is about 40 nm; nano Bi2MoO6:pH=7,160? and reacted at 12 h, the particle size is about 50 nm; nano Bi2Sn2O7:pH=7,700? and calcined to 8 h, the particle size is about 80 nm.The product of optimized condition were mixed physically with AP, RDX, HMX. A series of thermodynamic data was obtained by differential scanning calorimetry (DSC). According to Kissinger and Ozawa equation, we analyzed the changes of peak temperature and activation energy. Using the kinetic equation of non isothermal method, we obtained the dynamic mechanism equation of different catalysts catalyzing energetic materials. According to a series of dynamic data, we got the influence of different structure or the same structure but different pore nano metal composite oxides on energetic materials.Comparing the catalytic results, bismuth tungstate with the best catalytic effect is obtained, then production in batches and mixed into the double base propellant formulations. Using DSC and thermal dynamics equation, thermodynamic parameters and the most probable mechanism function of catalyst on the formulation were acquired. Meanwhile, the effect of catalysts on the burning rate, the pressure exponent and catalytic efficiency of double base propellant with bismuth tungstate were studied.