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THERMAL PROPERTIES
2. THERMAL PROPERTIES
2.1 Heat Capacity Determination. Heat capacity was measured by use of a dif-
ferential scanning calorimeter (DSC)l. In this instrument, a sample of explosive is
subjected to a linearly increasing temperature and the heat flow rate, dH/dt, is
monitored continuously. The heat capacity of the sample can be found from dH/dt
= mC,(dT/dt), where dH/dt = heat flow rate in calories per second, m = sample
mass in grams, C, = heat capacity in calories per gram per degree Celsius, T =
temperature in degree Celsius, and t = time. In using this equation to find C,, one
must know both dH/dt and the rate at which the temperature is increased or, more
commonly, use a material of known heat capacity to calibrate the instrument.
Synthetic sapphire, whose heat capacity is well known, is used as a reference
Explosive
DATB 1.834
DIPAM 1.79
HNS 1.74
HMX 1.90
PETN 1.770
RDX 1.804
TATB 1.938
Tetryl 1.73
Comp B-3
TNT
HMX-Based
PBX 9011
PBX 9404
PBX 9501
PETN-Based
XTX 8003
RDX-Based
PBX 9010
PBX 9407
XTX 8004
216
Table 2.01 HEAT CAPACITY DATA
Density Heat Capacity, C,
k/cm”)
(caVg-“C)
1.725
-_-
Pure Explosives
0.20 + (1.11 x 10-3)T - (1.81 x 10-+)TZ
0.235 + (6.2 x lo-“)T - (4.75 X lo-‘)T2
0.201 + (1.27 x 10-3)T - (2.39 x 10-B)T2
0.231 + (5.5 X lo-“)T
0.239 + (8.0 x lo-“)T
0.232 + (7.2 x lo-“)T
0.215 + (1.324 X 10-3)T - (2 X 10+)TZ
0.213 + (2.18 x lo-“)T - (3.73 x lo-‘)Tz
Castable Mixtures
0.234 + (1.03 X 10-3)T
0.137 + (2.09 x 10-3)T
0.254 + (7.5 x lo-‘)T
0.329 + (5.50 X lo-‘)T
Plastic-Bonded Explosives
Valid
Temperature
Range
(“(3
__-
_--
_--
37 < T < 167
37 < T < 127
37 < T < 167
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_--
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