The Chemistry of Powder and Explosives - Sciencemadness Dot Org

266 NITRIC ESTERS
than 20 hours of boiling with water. A solution of 0.1 gram of
Bismarck brown in 300 cc. of water gave better stabilization
of 30 grams of nitrocellulose in 1 hour than 10 boilings of 1 hour
each with separate 300-cc. portions of water.
Nitrocellulose, like all other nitric esters with the possible
exception of PETN,.is intrinsically unstable, even at ordinary
temperatures. Yet the decomposition of a thoroughly purified
sample is remarkably slow. Koehler and Marqueyrol 10 ° have
made a careful study of the decomposition of nitrocellulose at
various temperatures in the vacuum of a mercury pump. They
found that it evolved gas at the rate of about 0.7 cc. per gram
per day at 100°, 0.01 cc. per gram per day at 75°, and 0.0001 cc.
per gram per day at 40°.
A sample of CPi was freed from carbonate by digestion with
carbonated water and subsequent washing; it was dried thoroughly,
and 35.132 grams of the material (analyzing 211.2 cc.
NO per gram) was heated in vacuum at 75°. The results are
summarized in the following table, where all gas volumes have
been reduced to 0° and 760 mm. The residual gas, insoluble both
DURATION or HEATING
AT 75°
1st period (5 days)
2nd period (56 days)
3rd period (56 days)
4th period (56 days)
5th period (56 days)
6th period (56 days)
TOTAL
VOLUME,
CUBIC
CENTI-
METERS
2.25
1729
1855
1834
18.19
18.3
CUBIC
CENTI-
METERS
PER GRAM
PER DAY
0.0128
0.0088
0.00927
0.0080
0.0079
0.0084
COMPOSITION OP
NO
62.5
63.2
60.8
65.5
60.0
61.2
CO*
16.7
19.5
21.5
18.0
20.7
20.4
GAS,
Resid
20.8
173
17.6
16.5
19.6
183
in ferrous sulfate and in caustic soda solution, was analyzed and
was found to consist approximately of 46% carbon monoxide,
18% nitrous oxide, 35% nitrogen, and a trace of hydrocarbons.
After 309 days of heating at 75°, the temperature of the oven
was reduced, and the same sample of nitrocellulose was heated
in vacuum at 40° for 221 days. During this time it evolved a
total of 0.697 cc. of gas or 0.0001154 cc. per gram per day. The
same sample was then heated in vacuum at 100°, as follows.
100 Mem. poudres, 18, 101, 106 (1921).