| dc.description.abstract | The present investigation aims at synthesis, characterisation, reactivity, thermal properties and applications of some of the high?energy materials of hydrazine. The chemistry of hydrazine is of interest because of its endothermic heat of formation (?Hf = +12.0 Kcals/mole) and the presence of a potential N–N bond and four substitutable hydrogen atoms. Because of these, hydrazine has been used as a monopropellant and rocket fuel. Monomethylhydrazine (MMH) and unsymmetrical dimethylhydrazine (UDMH) have been used as rocket fuels. Transition?metal hydrazine perchlorate, nitrate and azide complexes have been investigated as primary explosives. Therefore it was considered interesting to study the hydrazine compounds as high?energy solids.
In Chapter I, a literature survey on high?energy materials and the chemistry of perchlorates, nitrates and azides in particular is presented. The scope and objective of the present investigations are highlighted.
Chapter II is devoted to the description of analytical procedures and instrumental methods employed in the present study. The instrumental methods used are differential thermal analysis (DTA), thermogravimetry (TG), impact?sensitivity measurements and spectroscopic techniques like infrared, UV, mass spectrometry and X?ray powder diffraction.
In Chapter III, synthesis and characterisation of hydrazine perchlorate (HP) hydrates (N?H?ClO?·0.5H?O and N?H?(ClO?)?·2H?O) and HP?ammoniates (N?H?ClO?·NH? and N?H?(ClO?)?·2NH?) have been discussed. Hydrazinium perchlorate monohydrate, N?H?ClO?·H?O, has been accidentally obtained and characterised. Thermal properties of N?H?ClO?·H?O are entirely different from those of N?H?ClO?·0.5H?O and N?H?(ClO?)?·2H?O. Hydrazine perchlorate ammoniates have been prepared by the reaction of anhydrous ammonia with the corresponding HP?hydrates. The HP?ammoniates are non?hygroscopic, stable and are not shock sensitive. These HP?ammoniates decompose violently at lower temperatures than the corresponding HP?hydrates.
Chapter III, Appendix: Doping of HP?1·0.5H?O with Mg²? ions results in a non?hygroscopic HP?1 salt. Infrared spectra and X?ray diffraction pattern are similar to HP?1·0.5H?O. However, Mg?doped HP?1·0.5H?O decomposes at a lower temperature.
Chapter IV: Very few hydrazine salts form hydrates. The nature of bonding of water molecules present in the hydrated hydrazine salts like N?H?ClO?·0.5H?O, N?H?(ClO?)?·5H?O and N?H?BrO?·2H?O has been investigated using infrared and thermal techniques. The presence of oxonium ions in these salts, especially at low temperature, has been proposed.
Chapter V: Metal hydrazine perchlorate, nitrate and azide complexes have been prepared by conventional as well as by a novel method. The conventional method involves the reaction of aqueous solutions of metal salts with alcoholic hydrazine hydrate. The novel method of preparing these hydrazine complexes involves the reaction of respective metal powders with a solution of ammonium salt (perchlorates, nitrates and azide) in hydrazine hydrate. These hydrazine complexes of the type M(N?H?)?X? where M = Mn, Fe, Co, Ni, etc., n = 2, 3 and
X = ClO??, NO?? and N?? have been characterised by chemical analysis and infrared spectra. Thermal properties of these complexes have been investigated using DTA and TG. They all decompose exothermically and explosively. Iron hydrazine nitrate, Fe(N?H?)?(NO?)?, decomposes at 40°C to yield Fe?O?. The observed impact?sensitivity values of metal hydrazine complexes indicate them to be primary explosives.
Hydrazine complexes of alkaline?earth azides have been prepared by the solid?state reaction of alkaline?earth metal oxides with hydrazinium azide at 120°C.
Chapter VI: Magnesium hydrazine azide, Mg(N?H?)?(N?)?, decomposes exothermically at 217°C with 51.00% weight loss to yield a light?blue coloured intermediate. The composition of this blue?coloured compound was of interest. Infrared spectrum of this intermediate showed a strong absorption at ~2100 cm?¹ indicating the possibility of formation of a dinitrogen complex. From the observed weight loss in TG, infrared, UV and mass spectrometry results, the composition of the intermediate appears to be
Mg(N?)?(N?H?)?. | |
