Polymorphism of high energy materials

The intimate connection between structure and properties is particularly acute in establishing the effectiveness and safety of high energy materials based on molecular compounds: chemical and physical stability, shelf-life, sensitivity to shock, pressure, and temperature. Compared to other classes of compounds treated in the book for which the polymorphs with less suitable properties are not chosen for use, and thus relegated to lower importance, for high energy materials the risks and dangers of lack of familiarity and control of the polymorphic system can entail considerable long-term risks. The chapter is divided into two major sections distinguishing between aliphatic materials and the aromatic materials, commonly known by their alphabetic moniker. Throughout the chapter the history of the development of many of these materials is provided, including some rather obscure references culled from formerly classified government research reports. A detailed discussion of the classic enigmatic polymorphism of trinitrotoluene (TNT) is presented.