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ALIPHATIC NITRO COMPOUNDS^591

Tetranitromethane forms very powerful explosive mixtures with combustible

substances, for example with nitrobenzene, and toluene. The explosive properties
of such mixtures were investigated in detail after an accidental explosion had oc-

curred in Münster University in 1920.

Naoum [63] gave the following data on the explosive properties of tetranitro-
methane and of its mixtures. Alone, tetranitromethane gives a lead block expansion

of only 40 cm^3 including 8 cm^3 contributed by the detonator.

A mixture of 83.8% of tetranitromethane, 4.9% of toluene and 11.3% of cotton

wool gives a lead block expansion of 435 cm^3 , i.e. of the order of the most powerful

explosive. The above mixture contains a 13% excess of oxygen.

A stoichiometric mixture, with its ingredients taken in such quantities as to

have all the oxygen consumed, containing 86% of tetranitromethane and 13.5%

of toluene gives an expansion of 465 cm

3

.

The density of the mixture is 1.45. According to the Chemisch Technische Reichs-

anstalt [64] measurements, its rate of detonation is exceptionally high:

in a glass tube of 12 mm diameter 7100 m/sec

in a steel tube of 25 mm diameter 8300-9300 m/sec

Behrens [65] measured the lead block expansions given by tetranitromethane

alone or in mixtures with nitrogen dioxide and benzene. Detonators of various

strengths from No. 1 to No. 8 were used as initiators. Tests with TNT and nitroglyc-

erine were made for comparison. The results obtained are shown in Table 128.

In another set of experiments Behrens investigated mixtures of tetranitro-

methane with benzene for their ability to detonate and for explosive power. He

found stoichiometric mixtures to be the most powerful.

TABLE 128

No.

of detonator Tetra-

nitromethane

Expansion, cm^3

Mixture Mixture

C(NO 2 ) 4 70% C(NO 2 ) 4 87% TNT Nitroglycerine

N 2 O 4 30% Benzene 13%

1 12 0 413 0 171

2 44 0 404 0 172

3 65 13 404 218 379

5 86 48 404 268 407

8 71 37 445 332 445

The explosive properties of nitrobenzene-tetranitromethane solutions were

examined in detail by Roth [62] who measured rates of detonation power (on

a 10.5 by 7 mm crusher gauge), and sensitiveness to impact, using nitroglycerine

and TNT as standards (Table 129). Lead block expansions are not included here

as they were not determined by standard methods.