What is an explosive?
Explosive is any chemical compound, mixture, or device, the primary or common purpose of which is to function by explosion, i.e., with substantially instantaneous release of gas and heat.
Explosives have been around for a long time, the first one used being gunpowder. It was invented in China or India sometime around 1000 AD.
In the 13thand 14th centuries, Roger Bacon and the Earl of Warwick introduced gunpowder to Europe. They used it for developing firearms and cannons. . From then on until the 1800s, no major developments took place in the field of explosives.
During the 19th century, many new materials such as nitric acid ester, nitrated paper (flash paper), nitro cotton (NC gun cotton), smokeless nitrocellulose, wood powder, blasting gelatine, picric acid and trinitrotoluene (TNT) were developed.
The 20th century saw the development of many new and more powerful explosives, such as RDX,
HMX, ADN, TNAZ, and HNIW.
What are High Energy Materials?
High energy materials are compounds which store chemical energy. They are either:
(1) single compounds like trinitrotoluene (TNT) containing both an oxidizing group, -NO2 and a reducing group or
(2) a mixture of an oxidizer and fuel elements, e.g., gun powder (KNO3 + C + S).
Such materials, on stimulation by mechanical, thermal or electrical devices, undergo rapid decomposition giving out heat, light, sound and large volumes of gases. The amount of energy released varies with the properties of the material such as composition, structure, density, heat of formation and decomposition, etc.
High energy materials are classified as explosives, propellants and fireworks depending upont heir properties and applications.
High Energy Explosives
CL-20 or Octa-Nitro-Cubane
CL-20 or Octa-Nitro-Cubane, is a Nitramine class of explosive 15 times as powerful as HMX. CL-20, so named after the China Lake facility of the Naval Air Weapons Station in California, US, was first synthesized by Dr. Arnold Nielson in 1987.
CL-20 looks like limestone or grainy talcum powder.The advantage with the CL-20 is its Reduced Sensitivity enabling easy handling and transportation of the lethal weaponry. CL-20 can substantially reduce the weight and size of the warhead while packing much more punch.
CL-20 -based Shaped Charges significantly improve the penetration over armours. It could be used in the bomb for the 120-mm main gun mounted on the MBT-Arjun.
But the costs of mass production of ICL-20 are still prohibitive. Compared to Rs.750 per kilogram it takes to produce RDX in the factory today, the HMX is worth about Rs.6,000 per kg while a kilogram of CL-20 costs a whopping Rs.70,000 per kg.
HMX or Octogen
Alternate names: His/Her Majesty Explosive or High Melting Explosive or High velocity Military Explosive, Cyclotetramethylenetetranitramine and homocyclonite.
Appearance: Odorless white or colorless crystals.
Uses: Component of plastic explosives (usually combined with TNT), component of rocket propellant, Detonation of nuclear devices, etc.
The HMX is more than four times as potent as the Research Developed Explosive or Royal Demolition Explosive or Cyclonite or Hexogen, commonly known as RDX.
LLM-105
2,6-Diamino-3,5-dinitropyrazine-1-oxide, known as LLM-105, is a typical nitro energetic material with some excellent properties, such as low sensitivity and high energy density.
The higher nitrogen content and density of LLM-105 lead to a higher detonation heat of 3.721 kJ/g.
Other Explosives
Nitroglycerin
Alternate names: 1,2,3-Propanetriol trinitrate, glycerol trinitrate, nitroglycerol, NG, trinitroglycerol, NTG, trinitrin, blasting oil and trinitroglycerine.
Appearance: Colorless oily liquid when pure, but turns a yellowish-brown when impure. Sweet burning smell.
Uses: Powerful high explosive used in dynamite, blasting gelatin, smokeless powder, and cordite. Can be used with nitrocellulose in some propellants, especially for rockets and missiles
TNT (Trinitrotoluene)
Appearance: Pale yellow solid compound in its basic state; odorless. TNT will turn brown toned with prolonged exposure to sunlight.
Uses: Primarily mines and demolition explosives. Also used in booster explosives and missile and rocket propellants. Military use decreased significantly after World War II.
RDX (Cyclotrimethylenetrinitramine)
Alternate Names: Cyclonite, hexogen, cyclotromethylene, trinitramine,Research Department Explosive, and Royal Demolition Explosive
Appearance: White or colorless crystals. Will appear red to pink in detonating cord
Uses: Primarily high explosive military warheads, mines, demolition explosives, booster explosives, missiles, and rocket propellants. Used in civilian oil well penetrators, heating fuel, and rat poison
PRACTICE QUESTIONS
QUES . What is the common characteristic of the chemical substances generally known as CL 20, HMX and LLM-105, which are sometimes talked about in media? UPSC PRELIMS 2025
(a) These are alternatives to hydro fluorocarbon refrigerants.
(b) These are explosives in military weapons.
(c) These are high energy fuels for cruise missiles.
(d) These are fuels for rocket propulsion.
Answer – (b)
