Preparation Of 3DOM Metal Oxides And Its Effect On Thermal Decomposition Properties Of Energetic Materials

Three-dimensional ordered macroporous（3DOM）materials have attracted much attention in catalysis due to their unique structure,adjustable composition,high mass transfer capacity,high stability,high electron transfer capacity and high specific surface area.By controlling the pore diameter and composition of the 3DOM material,it is expected to be used as an efficient combustion catalyst for the thermal decomposition of energetic materials.Based on the preparation and characterization of 3DOM metal oxides,the thermite reaction performance and catalytic activity for ammonium perchlorate（AP）were discussed.The specific research content are as follows:（1）Successfully synthesized polymethyl methacrylate（PMMA）microspheres with a diameter in the range of about 270-880 nm by soap-free emulsion polymerization and chosed the centrifugal method for assembly.The structure of PMMA template was characterized by SEM and FT-IR.（2）3DOM single metal oxides NiO,Fe₂O₃,Co₃O₄,Cu O and bimetallic oxides La Fe O₃,La Co O₃,La NiO₃,Ni Co₂O₄ and FeCo₂O₄ were synthesized by PMMA template method,and the pore diameter of FeCo₂O₄ was adjusted in the range of 140-306 nm.（3）3DOM Co₃O₄/Al,3DOM FeCo₂O₄/Al and 3DOM La Co O₃/Al were prepared by ultrasonic mixing method,electrostatic self-assembly method and P4VP self-assembly method.The electrostatic self-assembly method can modify the agglomeration of Al and make the two components in close contact,which will reduce the diffusion distance of reactive components and enhance the mass transfer.This conclusion is further verified by the DSC curve analysis results of synchronous thermal analyzer at 10℃·min^-1.The results show that the nano thermites prepared by electrostatic self-assembly method has the best thermite performance,and the total heat release of 220 nm 3DOM FeCo₂O₄/Al reaches 3577.00 J·g^-1.（4）The catalytic effect of different metal oxides on AP was tested by differential scanning calorimetry（DSC）at 20℃·min^-1.The results shows that 180 nm 3DOM FeCo₂O₄has the best catalytic activity,which is related to its high specific surface area and high adsorption capacity.The catalytic performance of FeCo₂O₄ for different energetic components were further tested at different heating rates.At 10℃·min^-1,FeCo₂O₄can reduce the thermal decomposition peak temperature of AP and CL-20 by 116.53℃and 7.67℃,respectively.（5）The effects of 3DOM Co₃O₄and 3DOM FeCo₂O₄ on the thermal behavior of AP, HMX and CL-20 were studied by non-isothermal calorimetry.The activation energy value of the thermal decomposition reaction was obtained by Kissinger and Ozawa equations.The results showed that the addition of different catalysts reduced the activation energy in varying degrees,and the catalytic activity of the 3DOM FeCo₂O₄ was better than that of Co₃O₄.The non-isothermal kinetic and thermodynamic parameters of CL-20 and its complexes were obtained by further combining with the calculus equation.The results showed that the addition of metal oxides can reduce the apparent activation energy of the thermal decomposition.