How Can you make Composition 4 explosive?

Answer:

C-4 (composition 4) is one of the popular plastic explosive(explosive chemical mix with plastic binder). It has two important advantages:

1. The explosive material which coated with plastic binder will make it less sensitive to heat and shock. Since it is stabilized, it is relatively safe to handle C-4. Only detonator or blasting cap can trigger the reaction. Lighting the C-4 with a match will just make it burn slowly, like a piece of wood. (In Vietnam, soldiers actually burn C-4 as an improvised cooking fire.) Even shooting the explosive with rifle won't trigger the reaction.
2. C-4 material is highly flexible. It can be molded into different shapes to change the direction of the explosion.

Explosive material in C-4 is cyclotrimethylene-trinitramine (royal demolition explosive / RDX). Cyclotrimethylene-trinitramine was first prepared in 1899 from nitric acid and methenamine by Henning. The flow chart below (please refer to reference below) shows the synthesis method uses methenamine (hexamethylenetetramine).

Besides the method above, cyclotrimethylene-trinitramine can also be synthesized from formaldehyde, ammonium nitrate and acetic anhydride. (Method developed by Ross and Schiessler' in 1940's)

Normally, C-4 is made up of explosives, plastic binder, plasticizer and, usually, marker or taggant chemicals such as 2,3-dimethyl-2,3-dinitrobutane (DMDNB) to help detect the explosive and identify its source. In 2004, Kenneth E. Lee discovered a reformulation of composition C-4 explosive for superior energetic performance and flexibility. (US Patent: 6887324)


Reference:

How C-4 explosive is made. Life Chemistry. Retrieved June 30, 2008, from http://life-chemistry.blogspot.com/2008/06/how-c-4-explosive-is-made.HTML  

Answer

RDX is thought to mean "Research Department Compound X." The Research Department was the part of the Ministry of Defence that made new military products, and they numbered the explosives they created. In the case of RDX, they were going to put a number on it later but just never got around to it.