  Solid propellants are energetic materials used to launch and propel rockets
and missiles. Although their history dates to the use of black powder more than
two millennia ago, greater performance demands and the need for "insensitive
munitions" that are resistant to accidental ignition have driven much research
and development over the past half-century. The focus of this review is the
material aspects of propellants, rather than their performance, with an
emphasis on the polymers that serve as binders for oxidizer particles and as
fuel for composite propellants. The prevalent modern binders are discussed
along with a discussion of the limitations of state-of-the-art modeling of
composite motors.
