Physicochemical Properties of Crystalline Materials

The polymeric materials that act as fuels and oxidizers are composed of atoms of nitrogen, oxygen, carbon, and hydrogen. The hydrocarbon structures act as fuel components, and the oxidizer fragments of-C-N02, -0-N02, -O-NO, or -N-N02 are attached to the hydrocarbon structure with covalent chemical bonds. 

Crystalline materials used as oxidizer components of propellants and explosives decompose thermally to produce gaseous fragments which act as oxidizer fragments. On the other hand, hydrocarbon polymers used as fuel components such as polyurethane and polybutadiene decompose endothermically and generate hydrogen, solid carbon, and other hydrocarbon fragments which act as fuel fragments. The mixtures of the hydrocarbon polymers and the crystalline materials are ener- 

Typical crystalline materials used as oxidizer components are divided into perchlorates, nitrates, nitro-compounds, nitramines, and metal azides. The polymeric materials used as fuel components are divided into nitrate esters, inert polymers, and azide polymers. The combinations of these oxidizer and fuel components give the desired ballistic characteristics of propellants or explosives. 

The perchlorates used for propellants and explosives are ammonium perchlorate (AP NH4CIO4), nitronium perchlorate (NP N02C104), and potassium perchlorate (KP KCIO4). AP is the major crystalline oxidizer used for composite rocket propellants. The oxygen molecules produced by the decomposition act as an oxidizer when AP particles are mixed with a polymeric fuel component, for example, 

This reaction produces significant amounts of heat and gaseous molecules, which yields high Isp, defined in Eq. (1.76). 

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