C-4 or Composition-4 is a common variety of military plastic explosive.
C-4 is made up of explosive, 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. As with many plastic explosives, the explosive material in C-4 is RDX (also known as cyclonite or cyclotrimethylene trinitramine) which makes up around 91?f the C-4 by weight. The plasticizer is di(2-ethylhexyl) or dioctyl sebacate (5.3? and the binder is polyisobutylene (2.1? Another plasticizer used is dioctyl adipate (DOA). A small amount of SAE 10 non-detergent motor oil (1.6?is also added. C-4 detonates at about 26,400 fps (8,050 meters per second).
C-4 is made by combining RDX slurry with binder dissolved in a solvent. The solvent is then evaporated away and the mixture is dried and filtered. The final material is an off-white solid with a feel similar to modelling clay.
C-4 is a 1960s improvement on a British World War II development called Nobel 808 which contained RDX, mineral oil, and lecithin. C-4 is part of a group of explosives along with C, C2 and C3, each containing different amounts of RDX.
The C stands for composition; the name is an abbreviation of Composition 4. The term composition is used for any stable explosive, and "Composition A" and "Composition B" are other known variants. Therefore, C-4 is correctly referred to as Composition-4.
A major advantage of C-4 is that it can easily be moulded into any desired shape. C-4 can be pressed into gaps/voids in buildings, bridges, equipment or machinery. Similarly, it can easily be inserted into empty shaped-charge cases of the type used by special forces. C-4 is also well known for its durability, reliability, and safety. It will not explode even if hit by a bullet, punched, cut, or thrown into a fire. The only reliable method for detonation is via a detonator or blasting cap. However, applying pressure in combination with heat can often cause detonation.
When the military or a demolition company uses C-4 they normally use 8–10 pounds of C-4 to demolish eight-inch-square steel beams, even though this is more explosive than is required. They do this to make sure that they have accomplished the job successfully.
British plastic explosive is referred to as PE4. Like C-4, it is an off-white solid and its explosive characteristics are nearly identical. The only difference between C-4 and PE4 is the type and proportion of plasticizer used.
C-4 is 1.34 times as explosive as Trinitrotoluene
Trinitrotoluene (TNT) is an explosive. Its empirical formula is C7H5N3O6.
The name for TNT is, in accordance with the nomenclature of the IUPAC, 2-methyl-1,3,5-trinitrobenzene. In this article the more common designation trinitrotoluene is used.
TNT was first synthesised by Joseph Wilbrand in 1863, and the first large-scale production began in Germany in 1891.
The explosive yield of TNT is considered the standard measure of strength of bombs and other explosives (see TNT equivalent).
Trinitrotoluene is in the form of pale yellow, needle-shaped crystals and can be distilled in a vacuum. It is difficult to dissolve TNT in water; it is more soluble in ether, acetone, benzene and pyridine. With its low melting point of 80.35 °C, TNT can be melted in water vapour and poured into forms. TNT is poisonous and skin contact can cause allergic reactions, causing the skin to turn a bright yellow-orange color.
Water solubility: 130 mg/L at 20 °C
Steam pressure at 20 °C: 1.5 -6 mbar
Detonation speed: 6700-7000 m/s 6900 m/s (density: 1,6 g/cm³)
Lead block test: 300 ml/10 g
Sensitivity to impact: 15 Nm (1.5 kpm)
Friction sensitivity: to 353 N (36 kp) no reaction
Some military testing grounds are contaminated with TNT. Wastewater from munitions programs including contamination of surface and subsurface waters may be colored pink as the result of TNT and RDX contamination. Such contamination, called pinkwater, may be difficult and expensive to remedy.
TNT is quite toxic. It can also be absorbed through the skin, and will cause irritation and bright yellow staining. During the First World War, munition workers who handled the chemical found that their skin turned bright yellow, which led to the nickname "canary girls" or simply "canaries" to describe such workers. TNT would also eventually make ginger hair turn green. A 1916 British Government inquiry on female workers at the Royal Arsenal, Woolwich found that 37?ad severe pains due to loss of appetite, nausea and constipation, 25?uffered from dermatitis, and 34?xperienced changes in menstruation. Before respirators and protective grease applied to the skin were introduced, about 100 workers died from the disease.
People exposed to trinitrotoluene over a prolonged period tend to experience anemia and abnormal liver functions. Blood and liver effects, spleen enlargement and other harmful effects on the immune system have also been found in animals that ingested or breathed trinitrotoluene. There is evidence that TNT adversely affects male fertility, and TNT is listed as a possible human carcinogen. Consumption of TNT produces black urine.
Answered By: Cristi@n - 10/27/2006