An Experimental Comparison of Selected Blue Flame Pyrotechnics

In this research, 10 different pyrotechnic blue flame compositions were designed and compared. Chromaticity and luminosity parameters of the flame were measured using Ocean Optics JAZ‐ULM VIS‐Spectrometer equipped with a cosine corrector. Color saturation, luminous intensity, specific luminous intensity, oxygen balance, burn rate, actual and theoretical maximum density, color coordinates (X, Y) are presented and discussed

Metal-fluorocarbon pyrolants. XIII: High performance infrared decoy flare compositions based on MgB2 and Mg2Si and Polytetrafluoroethylene/Viton®

In the presented work two experimental pyrolants for use in blackbody infrared decoy flares showing higher performance than baseline magnesium/polytetrafluoroethylene/Viton (R) (MTV) were investigated. These pyrolants are based on fuels hitherto unknown to pyrotechnics: magnesium diboride, MgB2, and dimagnesium silicide, Mg2Si. Both fuels were formulated with polytetrafluoroethylene, PTFE and a fluorocarbon binder Viton (R) (designated MbTV and MsTV). MsTV yields higher radiance, L? (W?cm-2?sr-1) in the mid infrared range (25 mu m) than MTV at same stoichiometry. The volumetric spectral efficiency E? (J?cm-3?sr-1) of MbTV is also superior to MTV. MbTV thus allows for size reduction of black body countermeasure flares and thereby has potential to enhance the survivability of aircraft in hostile environments. Due to its very high burning rate MsTV qualifies for first fire and igniter applications

Pyrene derived functionalized low molecular weight organic gelators and gels

Pyrene derived binary functionalized low molecular weight organic gelators (FLMOGs) and gels thereof in selected organic solvents were synthesized and characterized. The functionality refers to a functional group that does not take part in formation of the supramolecular gel network, but remains free and available for other purposes, such as to bind nanoparticles or other molecules into the gel structure. Functional groups were observed to disturb gel formation strongly, if they interact with each other within the same supramolecule due to the formation of competitive structures. Preventing such interactions restored the original gel properties. A gel with weaker supramolecular bonding than the binding between the functional groups was successfully made by separating the functional groups by distance. The $\pi-\pi$-interaction was found to be of negligible significance to the supramolecular binding energy, but probably essential to align the molecules to a one-dimensional chain and bring them into the range of van der Waals forces mainly responsible for the binding in this system. Solvent was observed to increase the binding energy of the supramolecule. All molecules were characterized by spectroscopic techniques and elemental analysis. Selected gels were characterized with rheometry, scanning electron microscopy, UV- and fluorescence spectroscopy. Gelation kinetics and hysteresis were measured by UV-spectroscopy and a fast gelation process was observed for all the gelators studied. The melting enthalpies were measured by DSC and calculated theoretically by PM3 level of theory

Effects of aluminum composites on the regression rates of solid fuels

Innovative, mechanically activated Al–polytetrafluoroethylene (PTFE) composites and ammonium perchlorate (AP) coated nano-sized aluminum (C-ALEX) were produced, characterized, and tested as solid fuel additives. The ballistics of fuel formulations based on hydroxylterminated polybutadiene (HTPB) was investigated in a microburner by a time-resolved technique for regression rate (rf) data reduction. Both Al-composites show promising results in terms of rf and mass burning rate enhancement. In particular, the C-ALEX showed a percent rf increase over the baseline (HTPB) of 27% at an oxidizer mass flux of 350 kg/(m2s), without requiring dedicated dispersion procedures. This performance enhancement was nearly constant over the whole investigated range