Studies On The Synthesis And Properties Of Deuterated Energetic Materials

Energetic materials are the power source of weapons and the material basis for weapon systems with long-range precision strikes and efficient damage.The upgrading of modern weapons is closely related to the development of energetic materials,which is a key technology for the development of weapons.Neutron technologies such as neutron diffraction and neutron scattering are new methods for studying the structures of materials,which has been developed in recent decades.It provides powerful research tools for exploring the internal structure of materials and crystal defects.Due to the lack of deuterated energetic materials,the neutron scattering and diffraction studies of energetic materials have not been reported.The research on the synthesis of important deuterated energetic materials is conducive to understand the effects of structure and crystal defects on the properties of energetic materials through neutron technology,which is of great significance to the engineering application of energetic materials.In this dissertation,HMX-d₈,RDX-d₆ and TKX-50-d₈ were synthesized starting from deuterated paraformaldehyde or deuterated hydroxylamine hydrochloride.The synthetic conditions of HMX were studied by DADN method starting from non-deuterated polyformaldehyde.The study shows that azeotropic distillation with t-butanol could reduce the hydrolysis of urotropine and thus increase the yield of urotropine.On the basis of the synthesis of non-deuterated HMX,deuterated HMX-d₈was successfully synthesized with a total yield of 58.5%starting from deuterated paraformaldehyde.The intermediates and target product were characterized by UV-Vis,FT-IR,¹H NMR,¹³C NMR,TG-DTG,DSC,XRD,and X-single crystal diffraction.The deuterated ratio of the HMX-d₈ was 99.75%using ¹H NMR with maleic anhydride as an internal standard.The purity of the synthesized HMX-d₈ was determined to be 99.27%by HPLC by area normalization method.Recrystallization of HMX-d₈ with nitric acid,acetone,or DMSO-H₂O,as well as thermal crystal phase conversion,?-,?-,?-and?-HMX-d₈ were successfully prepared.The DSC curves of?-HMX-d₈ under different heating rates were obtained.Calculation according to the Kissinger method and Ozawa method gave the thermal decomposition apparent chemical energy?E_a?,the pre exponential factor?A?,Arrhenuis equation ln K=73.59-337.775×10^3/RT,free energy??G^??=55.38 kJ·mol^-1,activation enthalpy??H^??=337.11 kJ·mol^-1,activation entropy??S^??=508.64 J/mol?k,and explosion critical temperature(T_bpo)=561.77 K.The deuterated RDX-d₆ was obtained starting from deuterated paraformaldehyde by direct nitralysis of deuterated urotropine(HMTA-d₁₂).The intermediate and final product were characterized by UV-vis,FT-IR,¹H NMR,¹³C NMR,TG-DTG,DSC,SEM,XRD,and single crystal diffraction.The deuterium ratio of the synthesized RDX-d₆ was measured to be 99.32%as indicated by ¹H NMR using maleic anhydride as internal standard.The purity of RDX-d₆ was 99.03%as determined by HPLC using area normalization method.The DSC curves of product under different heating rates were obtained.Calculation according to the Kissinger method and Ozawa method provided the thermal decomposition apparent chemical energy?E_a?,the pre exponential factor?A?,Arrhenuis RDX-d₆ equation ln K=40.31-174.315×10^3/RT,?G^?=34.34 kJ·mol^-1,?H^?=170.27 kJ·mol^-1,?S^?=267.68 J/mol·k,and T_bpo=520.75 K.The synthesis of 5,5'-bitetrazole-1,1'-dioxide dihydroxylamine?TKX-50?was studied via oximation,chloration,azidation,cyclization,and metathesis reactions starting from glyoxal?40%?.On this basis,the synthesis of deuterated 5,5'-tetrazole-1,1'-dioxide dihydroxyamine?TKX-50-d₈?was studied by H/D exchange method,sodium salt method,acidic aqueous solution method and sodium hydroxide neutralization method,respectively.The deuterated ratio of TKX-50-d₈ was 90.96%after quartic H/D exchanges;the deuterated ratio of TKX-50-d₈ synthesized by sodium salt method was 88.56%;the deuterated ratio of TKX-50-d₈ synthesized by acidic aqueous method was 93.63%;the deuterated ratio of TKX-50-d₈ synthesized by sodium hydroxide neutralization method was 97.70%,as indicated by ¹H NMR using dimethyl furandicarboxylate as internal standard.Furthermore,10g of TKX-50-d₈ was prepared by sodium hydroxide neutralization method.The intermediates and final product were characterized by UV-vis,FT-IR,¹H NMR,¹³C NMR,TG-DTG,DSC,SEM,and XRD.The DSC curves of product under different heating rates was obtained.Calculation according to the Kissinger method and Ozawa method gave the thermal decomposition apparent chemical energy?E_a?,the pre exponential factor?A?,the Arrhenuis TKX-50-d₆ equation lnk=35.59-153.55×10^3/RT,?G^?=31.64 kJ·mol^-1,?H^?=149.08 kJ·mol^-1,?S^?=234.63 J·mol^-1·K^-1,and T_bpo=514.82 K.