Dr. Sangeetha BalakrishnanPG Department of Chemistry

Women’s Christian CollegeChennai – 600 006

Explosives

Forensic Science PCH/NM/01

Explosions

Deflagration Detonation

Deflagration DetonationOxygen physically mixed with the fuel.

This oxygen bonds with other atoms in the fuel, which form weaker bonds than in O2. This requires less activation energy to break.

Oxygen chemically incorporated in the fuel.

Instantaneous explosion.

Eg.: Black powder (Potassium nitrate, charcoal and sulfur: 15:3:2)

ANFO (ammonium nitrate fuel oil)

NitroglycerineTNT

Explosives

Low Explosives High Explosives

Initiatingor

Primary Explosives

Non-initiatingor

Secondary explosives

Eg: lead azideLead styphanate

Low Explosion: Explosions that produce escaping gases of velocities less than the speed of sound.High Explosion: Explosions that produce escaping gases of velocities greater than the speed of sound.

Eg: RDXPETN

Eg: DynamiteTNT

Require a booster for explosion

Improvised Explosive Devices1. Vehicular Bombs

• Methods currently in use:1. Metal detectors2. Millimeter Wave Scanners3. Puffer Machine