R. Meyer J. Köhler A. Homburg Explosives

295 Stabilizers
Stabilizers
Stabilisatoren; stabilisateurs
Stabilizers are generally defined as compounds which, when added in
small amounts to other chemical compounds or mixtures, impart stability
to the latter.
In propellant chemistry, especially so in the case of nitrocellulosecontaining
powders, the stabilizers employed are compounds which,
owing to their chemical structure, prevent the acid-catalyzed decomposition
of nitrocellulose, nitroglycerine, and similar nitrate esters.
They exert their stabilizing effect by binding the decomposition products,
such as the free acid and nitrous gases; the stabilizers themselves
are converted into relatively stable compounds at the same
time. Neither stabilizers nor their secondary products should give a
chemical reaction (saponification) with nitroglycerine or nitrocellulose.
Compounds used as stabilizers are mostly substitution products of
urea and diphenylamine. Readily oxidizable compounds – higher alcohols,
camphor, unsaturated hydrocarbons (vaselines) – may also be
employed. For such compounds to be effective, their homogeneous
incorporation into the powder must be easy, they must not be too
volatile, and must not be leached out by water. Many stabilizers also
display plasticizing (gelatinizing) properties; accordingly, they have
both a stabilizing effect and – in the manufacture of powders – a
gelatinizing (softening) effect.
Pure stabilizers include:
diphenylamine
Akardite I (asym-diphenylurea)
Stabilizers with a gelatinizing effect include:
Centralite I (sym-diethyldiphenylurea)
Centralite II (sym-dimethyldiphenylurea)
Centralite III (methylethyldiphenylurea)
Akardite II (methyldiphenylurea)
Akardite III (ethyldiphenylurea)
Substituted urethanes:
ethyl- and methylphenylurethanes
diphenylurethane
Pure gelatinizers, without a stabilizing effect, include:
dibutyl phthalate
diamyl phthalate
camphor
For formulas and properties see appropriate keywords.