The Chemistry of Powder and Explosives - Sciencemadness Dot Org

DIAZONIUM SALTS 441
A 0.05-gram sample of lead styphnate in a test tube in a bath
of Wood's metal heated at a rate of 20° per minute explodes at
267-268°.
Wallbaum 53 determined the minimum charges of several primary
explosives necessary for initiating the explosion of PETN.
In the first series of tests, the PETN (0.4 gram) was tamped
down or pressed loosely into copper capsules 6.2 mm. in inside
diameter, and weighed amounts of the priming charges were
pressed down loosely on top. The weights of the priming charges
were decreased until one failure occurred in 10 tests with the
same weight of charge. In later series, the PETN was compressed
at 2000 kilograms per square centimeter. When the priming
charges were pressed loosely on the compressed PETN, considerably
larger amounts were generally necessary. One gram of lead
styphnate, however, was not able to initiate the explosion of the
compressed PETN. When the priming charges were pressed, on
top of the already compressed PETN, with pressures of 500,
1000, and 1500 kilograms per square centimeter, then it was
found that the tetracene and the fulminate were dead-pressed
but that the amounts of lead azide and silver azide which were
needed were practically the same as in the first series when both
the PETN and the priming charge were merely pressed loosely.
Wallbaum reports the results which are tabulated below.
Pressure on PETN, kg. per sq. cm. 0 2000 2000 2000 2000
Pressure on initiator, kg. per sq. cm. 0 0 500 1000 1500
PRIMARY EXPLOSIVE MINIMUM INITIATING CHARGE, GRAMS
Tetracene 016 0250 dead.pressed
Mercury fulminate (gray) 0 30 0 330 " "
Mercury fulminate (white) 030 0 340 " "
Lead styphnate 0.55 No detonation with 1 g.
Lead azide (technical) 0.04 0170 0.05 0.05 0.04
Lead azide (pure) . 0 015 0.100 0.01 0.01 0.01
Silver azide 0.005 0110 0.005 0.005 0.005
Diazonium Salts
Every student of organic chemistry has worked with diazonium
salts in solution. The substances arc commonly not isolated in
the solid state, for the dry materials are easily exploded by shock
and by friction, and numerous laboratory accidents have resulted
from their unintended crystallization and drying.
53 Z. ges. Schiess- u. Sprengstcffw., 34, 1267 161, 197 (1939).