Physicochemical Properties of Pyrolants

The physicochemical characteristics that constitute selection criteria for the chemicals used in pyrolants can be summarized as follows  

Melting-point temperature Decomposition temperature Volume change by phase transition Physical stability 

When a fuel-rich pyrolant burns in the atmosphere, oxygen molecules from the atmosphere diffuse into the initial combustion products of the pyrolant. The combustion products burn further and generate heat, light, and/or smoke in the atmosphere. A typical example is the combustion process in ducted rockets fuel-rich products generated in a gas generator are burnt completely in a combustion chamber after mixing with air pressurized by a shock wave that is taken in from the atmosphere. 

HMX and RDX are heated, deflagration combustion occurs with a burning rate of about 1 mm s at 1 MPa. However, when these nitramines are ignited by primers giving rise to shock waves, detonation combustion occurs with a burning rate of more than 7000 m s . The characteristics of combustion wave propagation are determined by the Chapman-Jouguet relationship described in Refs. [1-5]. 

---