Preparation And Characterization Of Nanocomposite Energetic Material Based On HMX And AP

Nanocomposite energy materials were widely used in solid propellant and other military fields with excellent structure and performance. But non-energetic materials are mostly used as matrix which is difficult to further improve energy level of the composites. In this paper, we find an energetic matrix EP with unique three-dimensional nano-network and use it as matrix to prepare a novel nanocomposite energy materials HMX/AP/EP, AP/EP. Then its structure and properties were characterized. Those materials not only have three-dimensional nano-structure, but also overcome energy loss brought by the current non-energetic matrix. This nanocomposites can solve the problem of nano-materials’agglomeration and improve thermal properties and mechanical properties of energetic materials significantly with the help of synergistic effect of nano-HMX, AP and EP, which are expected to become a kind of high energy and low sensitivity nanocomposite materials. The main contents are as follows:(1) Preparation and characterization of HMX/AP/EP Nanocomposite:The nanocomposite energetic material HMX/AP/EP was prepared by coprecipitation and freeze-drying method using EP as matrix. The oxygen balance of HMX/AP/EP nanocomposites was mediated by changing the mass ratio of HMX and AP. The structure of composites were characterized by SEM, EDS, FTIR, BET, XRD, IC. The results indicate that the structure of HMX/AP/EP nanocomposite is a 3D meshwork composed of fibers on which the HMX and AP particles uniformly deposit with the size of 50-200 nm. The specific surface area of HMX/AP/EP is 10 m2 g"1 much less than that of EP 34.7m2g-1.XRD and IR analyses further confirm that HMX and AP coexist in the meshes of EP fibers. TG-DSC test analysis indicates that EP could not only boost the decomposition of AP, but also enhance the interactions between AP and HMX. In addition, the thermal decomposition temperature of HMX/AP/EP is well below that of HMX and the decomposition heat of nanocomposite is up to 2570J g-1, much larger than that of pure HMX,1574 J g-1. Compared to HMX and mechanical mixture, HMX/AP/EP composite has lower impact sensitivity.(2) Preparation and Characterization of AP/EP Nanocomposite:The nanocomposite energetic material AP/EP was prepared by coprecipitation and freeze-drying method using EP as matrix. The structure of composites were characterized by SEM, EDS, FTIR, BET, XRD, IC. The results confirm that AP and EP are successful to combine together at molecular level. AP particles uniformly deposit on nano-network structure of EP and the average grain size of AP/EP composites are smaller than 100nm. TG-DSC test and the calculation of thermal decomposition kinetics parameters of AP/EP by Kissinger equation, AP/EP has good thermal stability and it’s decomposition temperature greatly advance about 50℃. Ea1=148KJ/mol, Ea2=384KJ/mol, EP/AP decompose difficultly because of its higher decomposition activation energy compare with EP. EP can boost decomposition of AP and further improve the energy level of the AP/EP composite. Meanwhile, the detonation properties of AP, EP, AP/EP calculated by the linear output thermodynamic equation indicate the detonation velocity and detonation pressure of AP/EP composite is better than others.EP is used as energetic matrix with three-dimensional network structure which has excellent mechanical properties and thermal properties, it can be combine with other energetic materials to prepare a series of nanocomposite energy materials, not only can further improve the energy level, but also can endow new performance of composite materials.