Chemistry of pyrotechnics

Chemistry of pyrotechnics

COMPONENTS OF HIGH-ENERGY MIXTURES

The high-energy chemist can greatly expand his repertoire of materials by preparing mixtures, combining an oxidizing material with a fuel to produce the exact heat output and burning rate needed for a particular application.

PYROTECHNIC PRINCIPLES

The secret to maximizing the rate of reaction for a given pyro- technic or explosive composition can be revealed in a single word - homogeneity.Any operation that increases the degree of intimacy energy mixture should lead to an enhancement of reactivity.

IGNITION AND PROPAGATION

For ignition to occur, a portion of the mixture must be heated to its ignition temperature, which is defined as the minimum temperature required for the initiation of a self-propagating reaction. Upon ignition, the reaction then proceeds on its own, in the absence of any additional energy input.

HEAT AND DELAY COMPOSITIONS

All pyrotechnic compositions evolve heat upon ignition, and this release of energy can be used to produce color, motion, smoke, and noise. There are applications as well for the chemically- produced heat itself, and these will be addressed in this chapter.

COLOR AND LIGHT PRODUCTION

The production of bright light and vivid color is the primary purpose of many pyrotechnic compositions. Light emission has a variety of applications, ranging from military signals and highway distress flares to spectacular aerial fireworks.

SMOKE AND SOUND

Most explosive and pyrotechnic reactions produce significant quantities of smoke, and this visible phenomenon may or may not be desirable. Smoke can obscure colored flames, and therefore attempts are made to keep the production of smoke to a minimum in such mixtures.