The Chemistry of Powder and Explosives - Sciencemadness Dot Org

308 SMOKELESS POWDER
when, in consequence of the disastrous explosion of the battleship
Jena in 1907 and of the battleship Liberte in 1911, both ascribed
to the spontaneous inflammation of the powder, and in consequence
of the researches of Marqueyrol, its use was discontinued
entirely. Indeed no powder containing amyl alcohol was manufactured
in France after October, 1910. Freshly manufactured
poudre BAm smelled of amyl alcohol; the alcohol was converted
by the products of the decomposition into the nitrous and nitric
esters, and these soon broke down to produce red fumes anew and
evil-smelling valerianic acid. The presence of the latter in the
powder was easily detected, and was taken as evidence that the
powder had become unstable. The Italians early used aniline as
a stabilizer for their military ballistite. This forms nitro derivatives
of aniline and of phenol, but it attacks nitrocellulose and
is now no longer used. As early as 1909, diphenylamine was being
used in the United States, in France, and in Germany, and, at
the present time, it is the most widely used stabilizer in smokeless
powder. The centralites (see below) also have a stabilizing
action in smokeless powder but are used primarily as non-volatile
solvents and deterrent coatings.
Calcium carbonate, either powdered limestone or precipitated
chalk, is used as an anti-acid in dynamite where it serves as-a
satisfactory stabilizer. Urea is used in dynamite and in celluloid.
It reacts with nitrous acid to produce nitrogen and carbon dioxide,
and is unsuitable for use in smokeless powder because the
gas bubbles destroy the homogeneity of the colloid and affect the
rate of burning. The small gas bubbles however commend it for
use in celluloid, for they produce an appearance of whiteness and
counteract the yellowing of age.
In addition to the ability of certain substances to combine with
the products of the decomposition of nitrocellulose, it is possible
that the same or other substances may have a positive or a negative
catalytic effect and may hasten or retard the decomposition
by their presence. But it has not yet been made clear what types
of chemical substance hasten the decomposition or why they do
so. Nitrogen dioxide hastens it. Pyridine hastens it, and a powder
containing 2 or 3% of pyridine will inflame spontaneously if
heated for half an hour at 110°. Powders containing tetryl are
very unstable, while those containing 10% of trinitronaphthalene
(which does-not react with the products of decomposition) are as