Synthesis And Properties Of 1-methyl-3,4,5-trinitropyrazole（MTNP）

The eternal theme during the development of explosive technological is to increase the energy levels. To enhance the combat effectiveness of weapons and ammunition, higher energy of explosives are required. To make the weapons safer to use, explosive loading must meet the requirement of insensitive. The ratio of melt-cast explosive, which takes TNT as carrier, was as high as 90% in mixed explosives for military. However, with the progress of technology, TNT, due to the high sensitivity, low density, detonation performance is not appealing and many other shortcomings, is unable to meet the requirements of modern military ammunition any more. Therefore, searching for new carrier of higher energy and lower sensitivity, which is a substitute of TNT, is becoming a hot topic recently.MTNP is an ideal substitute of TNT. Compared to other substitutes of TNT, MNTP has unparalleled advantages and characteristics: energy is close to RDX（D=8650 m·s-1, P=33.6 GPa, the value calculated）, IS>50J, is similar to TATB, Td=285℃（DSC） is similar to HMX, m.p.= 91.5℃, is similar to TNT. It is an excellent candidate for the carrier of melt-cast explosives, which have high energy and low sensitivity! Its characteristics are very attractive and its value of application is looking forward to further development.The work in this thesis focus on the synthesis of 1-methyl-3,4,5-nitropyrazole（MTNP）, which is an explosive of high energy and low sensitivity, including the synthesis through one-step and multi-step. Synthesis through one-step takes pyrazole as raw material, methylated by DMC, reactions under different conditions are studied, the influence of temperature, solvent volume and the amount of catalyst to methylation are discussed and the optimal condition, proved by amplified experiment, are discovered. The best time for the reaction is five hours, yield 73.3%. Then 1-nitropyrazole is nitrated by H2SO4/HNO3, heteropolyacids/HNO3 and montmorillonite K-10/Bi（NO₃）₃, but all result in failure. Synthesis through multi-step takes pyrazole as raw material, nitrated by HNO3/Ac2 O and then isomerization to give the intermediate 3,5-dinitropyrazole, many high-boiling solvents and solvent-free method are tried to optimize the processes, the influence of temperature to the isomerization are discussed, the optimal condition are discovered: the best solvent for isomerization is benzonitrile, yield>90%, the temperature is 180℃. The best temperature for the isomerization without solvent from 1-nitropyrazole to 3-nitropyrazole is 180℃, and the best temperature for the isomerization from 1,3-dinitropyrazole to 3,5-dinitropyrazole is 160℃, yields >99%. 3,5-dinitropyrazole is then nitrated by H2SO4/HNO3 to give 3,4,5-trinitropyrazole（TNP）, and finally methylated by Me2SO4 to give MTNP, the whole yield is 66.9%. The structure of MTNP is identificated by melting point, elemental analysis, infrared spectroscopy and nuclear magnetic resonance, and parts of its properties are measured: the thermal decomposition temperature is 240.4 ℃, the density is 1.7091 g·cm^-3, the impact sensitivity is 70 J, friction sensitivity is 360 N. The compatibility of MTNP with TKX-50, TNT, CL-20, RDX, Al, HTPB and PET are measured, the thermal decomposition kinetics and thermodynamic parameters of MTNP are calculated, cast experiment is carried out, the measured density is 1.77 g·cm^-3 and impact sensitivity is 45 J.