The Chemistry of Powder and Explosives - Sciencemadness Dot Org

FRICTION PRIMERS 453
which had been heated at 60° showed no evidence of decomposition.
The sample which had been heated at 75° was unchanged
in color but had a faint odor of mcthylamine and appeared
slightly moist. At 100° the substance gave off an amine odor.
The residue which remained after 24 hours of heating at 100°
consisted of a colorless liquid and needle crystals which were
soluble in water.
% WEIGHT LOST AT
In 2 hrs.
In 8 hrs.
In 24 hrs.
In 48 hrs.
60°
010
0 35
050
050
75°
0.25
0.60
130
2.25
100°
3.25
29 60
67.95
When hexamethylenetriperoxidediamine is boiled with water,
it disappears fairly rapidly, oxygen is given off, and the colorless
solution is found to contain ammonia, formaldehyde, ethylene
glycol, formic acid, and hexamethylenetetramine.
Friction Primers
Friction primers (friction tubes, friction igniters) are devices
for the production of fire by the friction of the thrust, either push
or pull, of a roughened rod or wire through a pellet of primer
composition. They are used for firing artillery in circumstances
where the propelling charge is loaded separately and is not enclosed
in a brass case supplied with a percussion primer. They
are sometimes crimped to an end of Bickford fuse for the purpose
of lighting it. They are sometimes used for lighting flares, etc.,
which are thrown overboard from airplanes. For this use, the
pull element of the primer is attached to the airplane by a length
of twine or wire which the weight of the falling flare first pulls
and then breaks off entirely.
The following table shows three compositions which have been
widely used in friction primers for artillery. All the materials
Potassium chlorate
Antimony sulfide
Sulfur
Meal powder
Ground glass
are in the powdered condition except in the fir^t mixture where
half of the potassium chlorate is powdered and half of it is- granu-
2 1
56.2
24 6
90
102
44 6
44 6
36
36
36