The Chemistry of Powder and Explosives - Sciencemadness Dot Org

DINITROCHLOROHYDRIN 221
can be frozen only with great difficulty, shows a strong tendency
to supercool, and can be kept for a long time at —20° without
depositing crystals. The solubility of dinitrochlorohydrin and
nitroglycerin in each other is so great that only small quantities
of nitroglycerin can be frozen out from the mixtures, even after
seeding, at winter temperatures. A mixture of 75 parts of nitroglycerin
and 25 parts of dinitrochlorohydrin is practically nonfreezing,
and yields a dynamite which is not significantly less
strong than one made from straight nitroglycerin.
Dinitrochlorohydrin does not take fire readily, and, if ignited,
burns rather slowly without detonating and with but little of the
sputtering which is characteristic of nitroglycerin mixtures. "Even
larger quantities of pure dinitrochlorohydrin in tin cans burn
without explosion when in a fire, so that liquid dinitrochlorohydrin
is permitted on German railroads in tin cans holding
25 kg., as a safe explosive for limited freight service in the 200 kg,
class, while liquid nitroglycerin is absolutely excluded." 36 Dinitrochlorohydrin
is more stable toward shock than nitroglycerin.
Naoum, working with a pure sample, was not able to secure a
first-rate explosion in the drop test. 37 A 2-kilogram weight
dropped from a height of 40 cm. or more gave a very slight
partial decomposition and a slight report, from a height of 75 cm.
or more, a somewhat more violent partial deflagration but in no
case a sharp report, and even a 10-kilogram weight dropped
from a height of 10 or 15 cm. gave a very weak partial decomposition.
The substance, however, is detonated readily by fulminate.
It gives in the Trauzl test a net expansion of 475 cc, or
79% of the 600-cc. expansion given by nitroglycerin, although its
heat of explosion is only about 71% of the heat of explosion of
nitroglycerin.
Dinitrochlorohydrin produces hydrogen chloride when it explodes.
This would tend to make it unsuitable for use in mining
explosives were it not for the fact that the incorporation into the
explosives of potassium or sodium nitrate sufficient to form
chloride with the chlorine of the dinitrochlorohydrin prevents it
altogether—and this amount of the nitrate is usually present
anyway for other reasons.
30 Naoum, ibid., p. 187.
37 Ibid., p. 188.