Studies On The Syntheses And Properties Of Multinitromethyl Energetic Compounds

The breakthroughs in field of energetic materials can improve the energy level of weapon systems,which plays an important role to enhance the national defense strength.Multinitromethyl(trinitromethyl and dinitromethyl)groups can be used to increase the oxygen balances and energetic properties of the formed energetic compounds due to their relatively high oxygen contents.But most reported multinitromethyl compounds are far away from applications because of their complex synthetic routes,low yields and poor thermal stabilities.Nowadays,studies on the syntheses of thermally stable multinitromethyl energetic compounds have become a hotspot.In this thesis,20 multinitromethyl energetic compounds of four kinds were synthesized and characterized.It mainly consists of the following four parts:2,2,2-Trinitroethyl nitrocarbamate(NTNC)was prepared by a two-step reaction in total yield of 98%,which consists directly amidation of 2,2,2-trinitroethanol and then nitration.The reaction processes are safe and simple.NTNC has a crystal density of 1.857g cm-3 and the density measured by a gas pycnometer is 1.7707 g·cm-3.DSC curve of NTNC shows a melting endothermic peak at 114.4 ? and a decomposition temperature of 165.8 ?.In addition,the compatibilities of NTNC with some common components of solid propellant and explosives were studied by DSC method,which laid a foundation for further study of its practical application in mixed explosives or propellant components.Five energetic salts(ammonium,guanidinium,aminoguanidinium,4-amino-1,2,4-triazolium and 3-amino-1,2,4-triazolium)based on 2,2,2-trinitroethoxycarbonyl nitroamine anion were synthesized by neutralization of NTNC with the corresponding bases.Their decomposition temperatures,densities,impact sensitivities and friction sensitivities were measured to be in ranges of 121.1-137.8 ?,1.753-1.827 g·cm-3,1-20 J and 14-36 N,respectively.Their detonation velocities and detonation pressures were calculated to be in ranges of 8213-8596 m·s-1 and 29.4-33.1 GPa,respectively.The 4-amino-1,2,4-triazolium salt has a density of 1.827 g·gm-3,decomposition temperature of 127.1 ?,impact sensitivity of 14 J,friction sensitivity of 34 N,calculated detonation pressure of 33.1 GPa and detonation velocity of 8596 m·s-1.Seven energetic salts(ammonium,guanidinium,aminoguanidinium,diamino-guanidinium,triaminoguanidinium,4-amino-1,2,4-triazolium and 3-amino-1,2,4-triazolium)based on 2-amino-1,1,5,5-tetranitro-4-oxo-3-aza-pentene anion were synthesized by nitration of 4,6-dihydroxy-2-methylpyrimidine and then quenching with aqueous solution containing corresponding cations.Their densities,thermal stabilities,impact sensitivities and friction sensitivities were in ranges of 1.745-1.880 g·cm-3,126.2-148.8 ?,1-16 J and 48-84 N,respectively.And their calculated detonation pressures and detonation velocities range from 28.6 to 34.3 GPa and 8037 to 8674 m·s-1.The ammonium salt has a density of 1.880 g·cm-3,decomposition temperature of 143.4 ? impact sensitivity of 8 J,friction sensitivity of 84 N,calculated detonation pressure of 34.3 GPa and detonation velocity of 8674 m·s-1.Two energetic potassium salts,potassium 3-dinitromethyl-4-nitraminofurazan and potassium 6-nitro-pyrazolo-[3,4-c]furazanate-5-oxide,were synthesized from 3-amino-4-chloroximinofurazan by nitration using N2O5/N2O4 and N2O5,respectively.The density,decomposition temperature,impact sensitivity,friction sensitivity calculated detonation pressure and detonation velocity of potassium 3-dinitromethyl-4-nitraminofurazan were 2.174 g·cm-3,281.4 ?,2 J,72 N,27.2 GPa and 7758 m·s-1,respectively,which make it a potential green primary explosive.The density,decomposition temperature,impact sensitivity and friction sensitivity of potassium 6-nitro-pyrazolo-[3,4-c]furazanate-5-oxide were 2.127 g·cm-3 200.5 ?,2 J and42N,what's more,its synthesis provides a new direction for the design of novel energetic compounds.In additon,six energetic salts(ammonium,hydroxylammonium,hydrazonium,guanidinium,aminoguanidinium and 3-amino-1,2,4-triazolium)based on 3-dinitromethyl-4-nitraminofurazan anion were also synthesized.Their decomposition temperatures,densities,impact sensitivities and friction sensitivities were determined to be in the ranges of 98.7-207.4 ?,1.614-1.930 g·cm-3,2-14 J and 64->360 N,respectively.And their calculated detonation pressures and detonation velocities range from 24.7 to 43.2 GPa and 7710 to 9662 m·s-1.Among them,the dihyuroxylammonium Sult has a density of 1.930 g·cm-3,decomposition temperature of 175.0 ?,impact sensitivity of 8 J,friction sensitivity of 64 N,calculated detonation pressure of 43.0 GPa and detonation velocity of 9646 m·s-1,which makes it possible to be used as high energetic materials.