Centralite is a gunshot residue

Gunshot residue

Gunshot residue is principally composed of burnt and unburnt particles from the explosive primer, the propellant, as well as components from the bullet, the cartridge case and the firearm used...

 also known as ethyl

Ethyl group

In chemistry, an ethyl group is an alkyl substituent derived from ethane . It has the formula -C2H5 and is very often abbreviated -Et.Ethylation is the formation of a compound by introduction of the ethyl functional group, C2H5....

 centralite. Its IUPAC name is 1,3-diethyl-1,3-diphenylurea. Ethyl centralite is insoluble in water, but is soluble in acetone

Acetone

Acetone is the organic compound with the formula 2CO, a colorless, mobile, flammable liquid, the simplest example of the ketones.Acetone is miscible with water and serves as an important solvent in its own right, typically as the solvent of choice for cleaning purposes in the laboratory...

, ethanol

Ethanol

Ethanol, also called ethyl alcohol, pure alcohol, grain alcohol, or drinking alcohol, is a volatile, flammable, colorless liquid. It is a psychoactive drug and one of the oldest recreational drugs. Best known as the type of alcohol found in alcoholic beverages, it is also used in thermometers, as a...

 and benzene

Benzene

Benzene is an organic chemical compound. It is composed of 6 carbon atoms in a ring, with 1 hydrogen atom attached to each carbon atom, with the molecular formula C6H6....

. It is mainly used as a burning rate

Burn rate (chemistry)

In chemistry, the burn rate is a measure of the linear combustion rate of a compound or substance such as a candle or a solid propellant. Burn rate is measured in length over time, such as "mm/second" or "inches/second". Burn rate is a property of combustible substance and it quantifies the...

 moderator and stabilizer for smokeless powder

Smokeless powder

Smokeless powder is the name given to a number of propellants used in firearms and artillery which produce negligible smoke when fired, unlike the older gunpowder which they replaced...

, and also a plasticizer

Plasticizer

Plasticizers or dispersants are additives that increase the plasticity or fluidity of the material to which they are added; these include plastics, cement, concrete, wallboard, and clay. Although the same compounds are often used for both plastics and concretes the desired effects and results are...

 for celluloid

Celluloid

Celluloid is the name of a class of compounds created from nitrocellulose and camphor, plus dyes and other agents. Generally regarded to be the first thermoplastic, it was first created as Parkesine in 1862 and as Xylonite in 1869, before being registered as Celluloid in 1870. Celluloid is...

.

Naming

The term "Centralite" was originally applied to dimethyldiphenylurea developed about 1906 at the German Central War Laboratory Zentralstelle fuer Wissentschaftlichtechnische Untersuchunggen in Neubabelsberg as a deterrent coating for smokeless powder in military rifle cartridges. Thereafter, all hydrocarbon-substituted symmetrical diphenyl urea compounds used as smokeless powder deterrents (or moderants) were called centralites after the laboratory. The preferred ethyl centralite became known as Centralite No. 1 and the original methyl centralite was identified as Centralite No. 2. Butyl centralite was also used as a celluloid plasticizer.

External links

• Fine Chemicals & Intermediates : Ethyl Centralite