Pyrolant

A pyrolant (from Greek pyros, fire) is an energetic material that generates hot flames upon combustion. Pyrolants are metal-based pyrotechnic compositions containing virtually any oxidizer. The term was originally coined by Kuwahara in 1992,^[1] in a paper on magnesium/Teflon/Viton, to distinguish between compositions that serve as propellants and those yielding hot flames which are not necessarily suitable for propellant purposes.

The word thermite also refers to metal-oxidizer mixtures, and is used interchangeably with, and more commonly than, "pyrolant".

A similar common term is propellant, which describes either a homogeneous or composite material that generates thrust upon combustion, but which may contain fuels instead of or in addition to the metals contained in thermites.

Metal-based pyrotechnic compositions, that is to say thermites or pyrolants, are generally characterized by high combustion temperatures (> 2000 K) and high amounts of condensed reaction products at equilibrium conditions such as metal oxides, fluorides and soot. Typical pyrolants find use as pyrotechnic initiators (Zr/BaCrO₄)^[2] or Zr/KClO₄, illuminating flare (Mg/NaNO₃)^[3] and decoy flare compositions (Mg/(C₂F₄)_n)^[4]

References

1. T. Kuwahara, T. Ochiachi, Burning Rate of Mg/TF Pyrolants, Proceedings of the 18th Int. Pyrotechnics Seminar, 1992, p. 539.
2. T. Kuwahara, T. Kohno, C. H. Wang, Static Electric Sensitivity Characteristics of Zr/$BaCrO_\mathrm{4}$, Pyrolants, Prop., Explos., Pyrotech. 29 2004, 56.
3. J. R. Ward, L. J. Decker, A. W. Barrows, Burning Rates of Pressed Strands of a Stoichiometric Magnesium-Sodium Nitrate Mix, Combust. Flame 51 1983, 121.
4. E.-C. Koch Metal/Fluorocarbon Pyrolants: VI. Combustion Behaviour and Radiation Properties of Magnesium/Poly(Carbon Monofluoride) Pyrolant, Prop., Explos., Pyrotech. 30 2005 209.