Synthesis Of Boron Energetic Compounds And Study On The Influence Of It On The Properties Of Propellants

Nowadays,the research on boron containing propellants are become a research hotspot.Thanks to the rise of non-metallic ionic energetic materials,the metal elements such as F,B,Mg,Al and Gu,which originally only appeared in primary explosives and mixed energetic materials,also is to introduce into the framework of single energetic materials.The combination of boron and nitrogen rich heterocycles via chemical bond is a way to improve the combustion performance of energetic compounds.It can effectively solve the problem that the oxides cover the surface of boron particles and affect the energy release while to ensure the high calorific value of propellant.It is the possible development direction of boron containing propellants,which is of great significance for the further study of energetic organic boron compounds.In this paper,5-amino-3-nitro-1,2,4-triazole was synthesized from dicyandiamide and hydrazine hydrochloride by condensation cyclization,rearrangement and oxidation.Diethylene glycol dimethyl ether was used as the high temperature reaction solvent to react with potassium borohydride at 145?for 48 hours,and the target product potassium tetra?5-amino-3-nitro-1,2,4-triazolyl?borate was obtained.The intermediates and target products were characterized by FT-IR,melting point analyzer,element analysis,X-ray photoelectron spectroscopy?XPS?and energy dispersive X-ray spectrometer?EDS?,and the synthesis conditions were optimized.In addition,the compatibility of the target product with the main components of the propellant was investigated by differential scanning calorimetry,4-triazolyl)potassium borate has no obvious interaction with silica and TPB;it is mixed with CL-20 and AI to improve the decomposition temperature,which is conducive to the stability of the propellant;it has obvious interaction with AP and RDX,so mixed use should be to avoid.A new synthesis method was used to synthesize the high purity intermediate3,5-dinitro-1,2,4-triazole?DNT?from 3,5-diamino-1,2,4-triazole?DAT?by diazotization and double decomposition.The potassium tetraborate?3,5-dinitro-1,2,4-triazolyl?was synthesized by the reaction of diethylene glycol dimethyl ether with potassium borohydride for 27 h at 110?,According to the reaction time,temperature and feed ratio,the optimal reaction condition of the intermediate was determined as reaction time 8h,reaction temperature 60?and feed ratio n?agdnt?:n?HCI?1:1.5.The intermediates were characterized by FT-IR,melting point analyzer and element analysis.However,the target product is an oil like liquid,which can not be test and characterize.In view of this problem,a possible solution is given.According to the stoichiometric ratio,barium perchlorate and barium perchlorate continue to react in the mixed solution of methanol or water to form to correspond barium borate.Barium salt and nitrogen rich sulfate react in the mixed solution of methanol and water to form borates of different cation forms.Nitrogen rich sulfates include but are not limite to hydrazine sulfate,ammonium sulfate and guanidine sulfate,which can change the solubility of substances by replacing cations,thus can provide the possibility of purification of target products.The energy properties of four?3,5-dinitro-1,2,4-triazolyl?hydrazine borate unit propellants and composite propellants in standard state?P_C:P₀=70:1?were studied by minimum free energy method.The results show that the theoretical specific impulse(I_SP)of hydrazine borate unit propellant is 2639.9 N·s/kg,which is almost equal to RDX,CL-20and HMX unit propellant,and much higher than AP and HMX.When hydrazine borate is used to replace the perchlorate in HTPB propellant,the theoretical specific impulse value of the propellant increases slowly and the maximum value is 2598.8N·s/kg.Substitution of AP in HTPB propellant with hydrazine borate can improve the overall energy level of propellant.When the mass fraction of hydrazine borate is 20%,the maximum specific impulse value of AP in CMDB propellant is 2451.5N·s/kg,which is 0.6%higher than that of the basic formula.Adding Al powder can significantly increase the energy level of the formula.