The Chemistry of Powder and Explosives - Sciencemadness Dot Org

DURATION
AT
1st period
2nd period
3rd period
OF HEATING
100°
(30 hrs.)
(8.5 hrs.)
(9 hrs.)
NITROCELLULOSE 267
TOTAL
VOLUME,
CUBIC
CENTI-
'METERS
29.09
8.57
8.09
CUBIC
CENTI-
METERS
PER GRAM
PER DAY
0.662
0.689 )
0.614 I
COMPOSITION OP GAS, %
NO COa Residue
51.9 24.1 24.0
68.1 17.6 143
The residual gas, neither NO nor CO2, was found to contain
about 64% of carbon monoxide, the remainder being nitrous
oxide and nitrogen with a trace of hydrocarbons. The nitrocellulose
left at the end of the experiment weighed 34.716 grams corresponding
to a loss of 1.24% of the weight of the original material,
It gave on analysis 209.9 cc. NO per gram corresponding to a
denitration per gram of 2.2 cc.
The gases from the decomposition of nitrocellulose in vacuum
contain nothing which attacks nitrocellulose. If the decomposition
occurs in air, the nitric oxide which is first produced
combines with oxygen to form nitrogen dioxide, and the red
fumes, which are acidic in the presence of moisture, attack the
nitrocellulose and promote its further decomposition. The decomposition
then, if it occurs in the presence of air or oxygen, is
self-catalyzed. The amount of nitric oxide which is produced
if the decomposition occurs in the absence of air, or the amount
of nitrogen dioxide which is produced in the first instance if the
decomposition occurs in the presence of air, is a function solely
of the mass of the sample. The extent to which the red fumes
attack the nitrocellulose depends, on the other hand, upon the
concentration of the gases and upon the area of the surface of
the sample which is accessible to their attack. The greater the
density of loading of the sample, the greater will be the concentration
of the red fumes. For the same density of loading, the
finer the state of subdivision of the sample, the greater will be
the surface. Pellets of compressed nitrocellulose, heated in the air,
decompose more rapidly than the same nitrocellulose in a fluffier
condition. The pellets give a poorer heat test (see below) but
obviously consist of material which has the same stability. Likewise,
nitrocellulose which has been dissolved in ether-alcohol and
precipitated by the addition of water, decomposes in the air more