Metal-Fluorocarbon Pyrolants. XII: Calciumsalze der 5-perfluoroalkylierten Tetrazole – Synthese, Charakterisierung und Leistungsbewertung als Oxidationsmittel in ternären Mischungen mit Magnesium und VitonTM/ Metal-Fluorocarbon Pyrolants. XII: Calcium Salts of 5-Perfluoroalkylated Tetrazoles – Synthesis, Characterization and Performance Evaluation as Oxidizers in Ternary Mixtures with Magnesium and VitonTM

Abstract

5H-Perfluoroalkyltetrazoles (alkyl = CF3, C2F5, C3F7) react with aqueous Ca(OH)2 to give the corresponding calcium salts 1, 2 and 3. Compounds 1 - 3, which form hydrates, were characterized by elemental analyses, differential heat flow calorimetry, multinuclear NMR, FTIR and Raman spectroscopy. A crystal structure determination was carried out on the solvate 2 ·2H2O·4CH3OH. Compounds 1 - 3 were tested as oxidizers in ternary pyrolant mixtures with magnesium and VitonTM. The burn rates, u (g s−1), of the pyrolants based on 1 show a distinct influence of the exothermicity of the primary reaction, whereas the burn rates of 2- and 3-based pyrolants do not show such behavior but display a steady increase of burn rate with increasing Mg content. At stoichiometries below 40 wt.-% Mg, the specific intensity Eλ (J g−1 sr−1) of the pyrolants based on 2 and 3 is superior to that of the standard mixture magnesium/polytetrafluoroethylene/VitonTM (MTV). This is assumed to be due to the expansion of the flame envelope by nitrogen.