TAGN

Tewa-Tagne, P., Briangon, S. Fessi, H. (2006). Spray-dried microparticles containing polymeric nanocapsules Formulation aspects, liquid phase interactions and particles characteristics. International Journal of Pharmaceutics, Vol. 325, 1-2, (November 2006), pp. (63-74), ISSN 0378-5173... 

Fig.4.22 Specific impulse, adiabatic flame temperature, and molecular mass of combustion products for TAGN-GAP composite propellants.

Fig. 4.23 Mole fractions of combustion products of TAGN-GAP composite propellants.

Fig. 5.3 Burning rates of HMX and TAGN showing that the burning rate of HMX is lower than that of TAGN.

The oxidizer fragment (HNO3) of TAGN is attached by an ionic bond in the molecular structure and the physicochemical processes of TAGN combustion are different from those of HMX and RDX, the oxidizer fragment of which (-N-NO2) is attached by a covalent bond in their molecular structures. Though the flame temperature of TAGN is lower than that of HMX by 1200 K, the value of the thermodynamic parameter (Tf/M y appears to be approximately the same for both materials. The... 

Fig. 5.7 shows scanning electron microphotographs of a TAGN surface before combustion (a) and after quenching (b). The quenched surface is prepared by a rapid pressure decay in the strand burner shown in Appendix B. The quenched sur-... 

The molecular structure of guanidine nitrate (GN CH6N4O3) is similar to that of TAGN, except that the latter has three additional amino groups ... 

Fig. 5.9 DTA and TG results for a thermally treated TAGN and for GN, showing the lower energetic nature of both materials.

Fig.5.10 Infrared spectra ofTAGN, thermally treated TAGN, and GN.

Fig. 5.11 Flame structure of TAGN showing a luminous flame standing above the burning surface the flame front approaches the burning surface as the pressure is increased (not shown).

The reaction rate is seen to increase linearly in an In [mj versus In p plot, and the overall order of the reaction in the gas phase is determined to be m = 1.78 based on the relationship m=n- d. This indicates that the reaction rate of TAGN in the gas phase is less pressure-sensitive than that of nitropolymer propellants for example, m = 2.5 for double-base propellants.PS]... 

The heat transfer process in the combustion wave of TAGN consists of three zones, similar to what was illustrated for HMX in Fig. 5.5. Zone I is the solid phase, the temperature of which increases exponentially from the initial temperature, Tg, to the decomposition temperature, without chemical reaction. Zone II is the condensed phase, the temperature of which increases from T to the burning surface temperature, T, in an exothermic reaction. Zone III is the gas phase, the temperature of which increases rapidly from to the final combustion temperature, Tg, in an exothermic reaction. 

Fig. 5.14 Rate of heat release at the burning surface of TAGN as a function of pressure.

Kubota, N., Hirata, N., and Sakamoto, S., Combustion Mechanism of TAGN, 21 st Symposium (International) on Combustion, The Combustion Institute, Pittsburgh, PA, 1986, pp. 1925-1931. 

Table 7.7 Physicochemical properties of TAGN-GAP and HMX-GAP propellants composed of cap(0-80)-...

Fig. 7.59 Burning rates and temperature sensitivity thereof for TAGN-GAP composite propeiiant composed of...

Similar to nitramine composite propellants and TAGN composite propellants, AN composite propellants produce halogen-free combustion products and thus represent smokeless propellants. However, their ballistic properties are inferior to those of other composite propellants the burning rate is too low and the pressure exponent is too high to permit fabrication of rocket propellant grains. In addition, the mechanical properties of AN composite propellants vary with temperature due to the phase transitions of AN particles. 

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