Synthesis,Structure And Properties Of C-N Bonded Bitriazoles And Their Salts

Bis-triazole compounds not only have high enthalpy of formation,high nitrogen content,high thermal stability,but also have more modification sites.By introducing different groups or forming salts,people can better design energetic compounds with superior performance according to the actual needs.Bis-triazole linked by C-N bonds are rarely reported.The heat of formation of C-N single bond is higher than that of C-C single bond.The amount of acid hydrogen can be reduced by connecting two triazole rings with C-N bond.Therefore,they are a kind of energetic materials with wide application prospectsIn this thesis,3-hydrazinium-4-amino-1H-1,2,4-triazolium dichloride（HATr-2HCl）was synthesized from triaminoguanidine hydrochloride and formic acid by cyclization.Then,HATr-2HCl reacts with dicyandiamine to form 3,4’,5-triamino-4’H-[1,3’-bis（1,2,4-triazole）]（TADT）.TADT reacts with nitric acid and perchloric acid to form TADT（NO₃）,TADT（ClO₄）.After that,TADT was nitrated.The nitration product 5-amino-3,4’-dinitramimo-4’H-[1,3’-bis（1,2,4-triazole）]（ADNABT）reacts with energetic cations with high nitrogen content to form a series of energetic ionic salts[（NH₄）₂（ADNABT）,（N₂H₅）₂（ADNABT）and（NH₃OH）₂（ADNABT）].ADNABT can also react with metal bases to form metal salts[Na₂（ADNABT）（H₂O）₄ and K₂（ADNABT）（H₂O）₂].All the prepared compounds were characterized by elemental analysis,NMR and IR.The single crystals of TADT,TADT（NO₃）,TADT（ClO₄）,Na₂（ADNABT）（H₂O）₄ and K₂（ADNABT）（H₂O）₂ were obtained and determined which lists as below:TADT:C₄H₇N₉,Monoclinic,C2/c;TADT（NO₃）:C₄H₈N₁₀O₃,Monoclinic,P2₁/c;TADT（ClO₄）:C₄H₉Cl N₉O₄,Triclinic,P-1（2）;Na₂（ADNABT）（H₂O）₄:C₄H₁₁N₁₁Na₂O₈,Monoclinic,P2₁/c;K₂（ADNABT）（H₂O）₂:C₄H₇N₁₁K₂O₆,Triclinic,P-1In order to study the thermal behavior of bitriazole compounds,the differential scanning calorimetry（DSC）and thermogravimetry（TG）techniques were used to measure the thermal decomposition process of the compounds with C-N bond under a non-isothermal condition.The thermal decomposition kinetic parameters and thermal decomposition kinetics equations were obtained by Kissinger,Ozawa and the integral method.The entropy of activation,enthalpy of activation and Gibbs free energy of activation of compounds were obtained.To evaluate the thermal safety of the as-prepared compounds,the self-accelerating decomposition temperature,the critical temperatures of thermal explosion and the thermal ignition temperature were calculated.The detonation properties of the compounds,including the detonation velocity and detonation pressure of TADT,TADT（NO₃）were predicted from the nitrogen equivalent equations.