Design And Preparation Of CL-20-based Eutectic Oxidant

In the field of free radical energetic materials,hexanitrohexaazaisowurtzitane(CL-20)with high energy density and ammonium dinitroamide(ADN)with excellent oxygen balance can increase the energy of solid propellants by using oxidants.CL-20 has problems such as high mechanical sensitivity and low oxygen balance.ADN has shortcomings such as easy moisture absorption and low energy.For CL-20,ADN and other oxidants,co-crystal modification becomes an elevated solid.According to the performance requirements of solid propellants for oxidants,the performance advantages and disadvantages of various oxidants in the propellant formulations are analyzed.Summarizes the co-crystal modification of CL-20,ADN and other oxidants in terms of mechanical sensitivity,hygroscopicity,oxygen balance,etc,summarizes the performance advantages and disadvantages of the currently reported co-crystal oxidizer raw materials and their preparation and application processes Existing problems.The crystal structure prediction and molecular dynamics simulation of CL-20/H₂O₂,CL-20/N₂O,and CL-20/ADN were carried out by Materials Studio software,and the CL-20/H₂O₂co-crystal was successfully prepared by solution crystallization,CL-20/N₂O co-crystal,CL-20/ADN co-crystal.Using scanning electron microscopy(SEM),infrared spectroscopy(FT-IR),differential scanning calorimetry(DSC)and other methods to characterize the target co-crystal,and test the density,impact sensitivity,friction sensitivity,moisture absorption and other parameters.CL-20 and H₂O₂may form high-density orthorhombic(Pbca space group)and low-density monoclinic(C2/c space group)two types of co-crystal,two co-crystal(molar ratio is 2?1)The theoretical density of CL-20 is lower than that of CL-20.Hydrogen bonds and van der Waals forces are the main driving forces for the formation of CL-20/H₂O₂co-crystal.The low binding energy between components and the increase in the average bond length of the bonds make CL-20/H₂O₂.The co-crystal mechanical sensitivity is slightly higher than that of the raw material CL-20.The CL-20/H₂O₂co-crystal(OB=-8.79%)has a higher oxygen balance than CL-20(OB=-10.95%),and its sensitivity and thermal stability are similar to CL-20.CL-20 and N₂O may form an orthorhombic co-crystal(Pbca space group).The unit cell parameters are close to?-CL-20.The theoretical density of CL-20/N₂O co-crystal(molar ratio 2?1)is lower than that of CL-20.Van der Waals force is the main driving force for the formation of CL-20/N₂O co-crystal;CL-20/N₂O co-crystal(OB=-8.69%)has better oxygen balance than CL-20,and safety performance is better than that of raw material CL-20,and the stability is similar to CL-20.The possible space groups of CL-20/ADN co-crystal(molar ratio 2?1)are P-1,P2₁,P2₁2₁2₁,the density is between CL-20 and ADN,and the hydrogen bond and van der Waals force are CL-20/ADN The main driving force for the formation of co-crystal,oxygen balance(OB=-5.6%)is better than CL-20,hydrogen bond and van der Waals force improve the thermal stability of CL-20/ADN co-crystal,CL-20/ADN co-crystal phase It has a higher thermal decomposition temperature than the raw material CL-20,the impact sensitivity is better than that of the raw material CL-20,and the moisture absorption rate is lower than that of the raw material ADN.