Chemistry is a important part of many engineering branches. Pyrotechnics is one of these branches, and in this article, we will mention and describe some of the basic but interesting facts related to energetic materials. An explosive material is a material that is more or less chemically stable, and can, by initiation, cause a sudden expansion of matter, that is often accompanied with the production of pressure and heat. Explosions are mostly very loud, and are acompanied by a bright flash.

There are two basic groups of explosives: low and high explosives. This article will mostly describe facts related to the latter type.

The group of high explosives can further be devided into more groups: primary, secundary and possibly tertiary as well. Primary explosives are the most sensitive and because of that, most dangerous group of explosives. They can be sensitive to shock, friction, and heat. Some can even be affected negativaly with visible light, or with electromagnetic radiation of other wavelenghts. Some of the examples of primary explosives are acetone peroxide, methyl ethyl ketone peroxide, mercury fulminate, mercury azide, and others.

Secondary explosives are the other mentioned main group of explosives. They are characterized by greater (shock, friction and heat) stability. Because of that, they are used as the main explosive in most cases (while the primary explosives mainly find their use in detonators, in small quantities, thereby lowering the risk to an acceptable level). Some secondary explosives are stable to the extent that they can actually be destroyed by burning them, if such a action is neccessary. On the other hand, there are also explosives that are unusually sensitive/stable. For example, trinitroglycerine can be set on fire, (it burns with a nice and bright white flame), but at the same time, if you drop a test tube filled with the mentioned compound, of a height of 1-2 meters, lets just say that the result of that would be very healthy for your life.

Except for these main groups of explosives within the field of high explosives, it is neccessary to mention the possible tertiary group aswell. Explosives of this group show even greater shock, friction and heat stability, making them hard to detonate even with larger quantities of primary explosives. Because of that, they are mostly detonated using explosive boosters. These boosters are mostly just a greater amount of secondary explosive that is detonated with a primary explosive, so that detonation of the tertiary explosive could be achieved. Ammonium nitrate, and its composite explosives (in example ANFO), could be mentioned as typical examples.

Pyrotechnics as an engineering branch has lot to do with the science of chemistry, so if one is interested in finding out more and understending basic pyrotechnic principles, it’s a good idea to start learning with the help of basic tutorials regarding chemistry.