May 27, 2008

Environmentally Friendly Bombs Planned

New explosives could be more powerful and safer to handle
than TNT and other conventional explosives and would also be more
environmentally friendly.

TNT, RDX and other explosives commonly used in military
and industrial applications often generate toxic gases upon detonation
that pollute the environment. Moreover, the explosives themselves are
toxic and can find their way into the environment due to incomplete
detonation and as unexploded ordnance. They are also extremely
dangerous to handle, as they are highly sensitive to physical shock,
such as hard impacts and electric sparks.

To make safer, more environmentally friendly explosives, scientists
in Germany turned to a recently explored class of materials called
tetrazoles. These derive most of their explosive energy from nitrogen
instead of carbon as TNT and others do.

Tiny bombs were made from two promising tetrazoles with the
alphabet-soup names of HBT and G2ZT. These materials proved less apt to
explode accidentally than conventional explosives.

After the bombs were detonated in the laboratory,
G2ZT also proved as powerful than TNT, and HBT more powerful than TNT
and comparable to RDX, said researcher Thomas Klapötke, a chemist at
the University of Munich in Germany.

In initial experiments, G2ZT and HBT produced fewer toxic byproducts
than common explosives. Still, they did generate some dangerous
hydrogen cyanide gas. But mixing these compounds with oxidizers not
only avoids making hydrogen cyanide, but also improved performance,
Klapötke said.

These compounds have great potential, "especially for large caliber naval and tank guns," Klapötke added.

Klapötke and his colleague Carles Miró Sabate are scheduled to detail their findings in the June 24 issue of the journal Chemistry of Materials.

The research was financially supported by the Ludwig-Maximilian
University of Munich, the Fonds der Chemischen Industrie, the European
Research Office of the U.S. Army Research Laboratory, the U.S. Army's
Armament Research, Development and Engineering Center, and the
Bundeswehr Research Institute for Materials, Explosives, Fuels and