Thermal behavior, decomposition mechanism and thermal safety of 5,7-diamino-4,6-dinitrobenzenfuroxan (CL-14)

Article abstract of DOI:10.1007/s10973-015-4992-3

Thermal decomposition kinetics and mechanism of the high-energetic material 5,7-diamino-4,6-dinitrobenzenfuroxan (CL-14) were determined by differential scanning calorimetry (DSC), rapid scanning Fourier transform infrared spectroscopy, and simultaneous thermogravimetric and DSC analyses, coupled with FT-IR and mass spectroscopy. To evaluate the thermal safety of 5,7-diamino-4,6-dinitrobenzenfuroxan (CL-14), its specific heat capacity (C_p) was measured by DSC, and thermal conductivity (λ) was estimated. Kinetic parameters and heat of exothermic decomposition reaction of CL-14 were obtained by analysis of DSC curves. Kinetic parameters used to evaluate the thermal safety of CL-14, such as self-accelerating decomposition temperature (T_SADT), critical temperature of thermal explosion (T_b) and impact sensitivity (H₅₀), were obtained. Results showed that for CL-14, T_SADT?=?282.0?°C and T_b?=?307.9?°C, whereas H₅₀?=?39.79?cm, revealing that CL-14 had better thermal safety and heat resistance than HMX, RDX and GNTO.

Full text of DOI:10.1007/s10973-015-4992-3

J Therm Anal Calorim
DOI 10.1007/s10973-015-4992-3
Thermal behavior, decomposition mechanism and thermal safety
of 5,7-diamino-4,6-dinitrobenzenfuroxan (CL-14)
1
1
1
1
•
Xiao-Long Fu
1
•
Xue-Zhong Fan
1
•
Bo-Zhou Wang
•
Huan Huo
Ji-Zhen Li
•
Rong-Zu Hu
Received: 20 March 2015 / Accepted: 16 August 2015
Ó Akad e´ miai Kiad o´ , Budapest, Hungary 2015
Abstract Thermal decomposition kinetics and mecha-
nism of the high-energetic material 5,7-diamino-4,6-dini-
trobenzenfuroxan (CL-14) were determined by differential
scanning calorimetry (DSC), rapid scanning Fourier
transform infrared spectroscopy, and simultaneous ther-
mogravimetric and DSC analyses, coupled with FT-IR and
mass spectroscopy. To evaluate the thermal safety of 5,7-
diamino-4,6-dinitrobenzenfuroxan (CL-14), its specific
Introduction
Benzenfuroxan has attracted attention as high-energetic
materials (HEMs) because of its structural peculiarities
and high densities [1–4]. The densities of explosive
molecules and velocity of detonation can be increased
when nitro groups were replaced with furoxan groups
[5–7]. Meanwhile, the introduction of amino groups to
explosive molecules can further enhance heat resistance
and density, as well as decrease impact sensitivity [8–11].
In view of improvements in thermal stability and insen-
sitivity, 5,7-diamino-4,6-dinitrobenzenfuroxan (CL-14)
has been studied as substitute for several traditional
energetic materials, such as 1,3,5-triamino-2,4,6-trini-
trobenzene (TATB), cyclotrimethylene trinitramine (RDX)
and cyclotetramethylene tetranitramine (HMX) [12].
CL-14 can be used as HEMs in propellants, explosives and
gun powders because of its high density, appropriate
detonation velocity and low sensitivity [13, 14]. The
synthesis of CL-14 was reported in the literature [15]. The
melting point and mechanical properties of CL-14-based
PBXs were investigated [12]. In addition, the salts of CL-
heat capacity (C ) was measured by DSC, and thermal
p
conductivity (k) was estimated. Kinetic parameters and
heat of exothermic decomposition reaction of CL-14 were
obtained by analysis of DSC curves. Kinetic parameters
used to evaluate the thermal safety of CL-14, such as self-
accelerating decomposition temperature (TSADT), critical
temperature of thermal explosion (T ) and impact sensi-
b
tivity (H ), were obtained. Results showed that for
5
0
CL-14, TSADT = 282.0 °C and T = 307.9 °C, whereas
b
H50 = 39.79 cm, revealing that CL-14 had better thermal
safety and heat resistance than HMX, RDX and GNTO.
Keywords Applied chemistry Á 5,7-Diamino-4,6-
dinitrobenzenfuroxan Á Thermal decomposition Á Thermal
safety Á RSFT-IR Á TG-DSC-MS-FT-IR
14 were synthesized, and the mechanical sensitivities of
the salts were tested [16].
Modern ordinance dictates strong requirements for
HEMs with low impact and shock insensitivity, good
thermal stability and better performance [17–20]. Among
the study methods of HEMs, thermal analysis study is
important not only for understanding of the kinetics of their
thermal decomposition but also for assessing the effect of
their exothermic decomposition on the potential hazardous
in their processing, handling and storage [21–23]. Kinetic
studies also provide useful information on thermal stability
of HEMs under different thermal environment in storage
[24–26]. However, the kinetics and mechanism of the
&
Xiao-Long Fu
fuxiaolong204@163.com
1
Xi’an Modern Chemistry Research Institute, Xi’an 710065,
China
123

X.-L. Fu et al.
1
3
decomposition and the decomposition products of CL-14
are not documented.
C NMR(DMSO-d , 125 MHz, d, ppm): 150.52(1C),
6
146.60(1C), 143.91(1C), 115.26(1C), 106.91(1C), 105.68(1C).
In this work, the thermal behaviors, decomposition
kinetics and mechanism as well as thermal safety of CL-14
have been experimentally investigated by several state-of-
the-art techniques, such as differential scanning calorime-
try (DSC) and thermogravimetric analyzer (TGA). Using
the original DSC data, the critical temperature of thermal
Anal. calcd for C H O N (%): C 28.13, H 1.563,
4 6 6
6
N 32.8 l.
Found C 28.37, H l.617, N 32.54.
Equipment and experimentation
Differential scanning calorimetry (DSC)
explosion (T ), self-accelerating decomposition tempera-
b
ture (TSADT) and the impact sensitivity (H ) were esti-
50
mated. Thus, the thermal safety of CL-14 was evaluated,
which is useful for evaluating the process of the explosion
from the thermal decomposition.
The DSC experiments for CL-14 were performed by using a
Model 910S DSC instrument (TA, USA). The CL-14 sample
was placed in aluminum pans. Dry, oxygen-free nitrogen
-
1
was used to purge the DSC at a rate of 50 mL min . The
-
1
heating rates were 5, 10, 15 and 20 °C min from ambient
temperature to 360 °C, using a sample mass of 2.5 mg.
Experimental
Materials
TG-DSC-MS-FT-IR
CL-14 prepared by our work group is a yellow powder with
[99.5 % purity. The synthesis of CL-14 is shown in
Scheme 1. The structure and composition of CL-14 are as
Thermogravimetric and differential scanning calorimetry
(TG-DSC) TG-DSC curves were obtained using the
Model 449C TG-DSC Instrument (Netzsch, Inc., Ger-
many). The thermal decomposition experiment was con-
ducted in the range of 35–380 °C, with a heating rate of
follows.
NMR spectra were recorded on a Bruker 500-MHz
NMR spectrometer using DMSO-d6, as the solvent with
tetramethylsilane as the internal standard. Elemental anal-
-
1
10 °C min , and under a nitrogen atmosphere (flow rate
-
1
ysis was performed by PE-2400 instrument.
1
of 75 L min ). TG and DSC curves obtained under the
same conditions overlapped with each other, indicating that
the reproducibility of the tests was satisfactory.
H NMR(DMSO-d , 500 MHz, d, ppm): 10.01(d,
6
J = 7.5 Hz, 2H, NH ), 10.85(d, J = 5.0 Hz, 2H, NH ).
2
2
Scheme 1 The preparation
route of CL-14
Cl
N3
O N
NO2
2
O N
NO2
2
NaN3
AcOH
NO2
NO2
NO2
NO2
H N
2
N
N
NaHCO3
O
O
N
NH2OH·HCl
N
O N
2
O N
2
NH2
O
O
CL-14
1
23

Thermal behavior, decomposition mechanism and thermal safety of…
Fourier transform infrared spectroscopy (FT-IR) FT-IR
100
1
00
TG
301.35 °C
spectra were carried out on a FT-IR spectrometer (Nicolet
90
80
70
5
700, USA) operating in absorption mode over the fre-
-
1
8
0
quency range of 4000–400 cm . The temperature of the
transfer line was maintained in the range from ambient
temperature to 380 °C.
60
mass loss: 81%
60
5
4
3
0
0
0
Mass spectroscopy analysis (MS) Mass spectra were
recorded using a Quadruple Mass Spectrometer (Netzsch
QMS403, Germany). The evolved gases during thermal
decomposition experiments were directly transferred by
means of a transfer line (heated to 380 °C) and detected by
mass spectrometer.
4
2
0
0
DSC
20
0
100
200
300
400
500
Temperature/°C
Fig. 1 TG-DSC curve of CL-14 by TG-DSC-MS-FT-IR
Rapid scanning Fourier transform infrared spectroscopy
(
RSFT-IR)
temperature was reported to be 308.5 °C in the literature
27] and may be caused by differences in the instrument
[
RSFT-IR measurements were detected using a model
NEXUS 870 FT-IR spectrophotometer (Nicolet Instru-
ments Co., USA) and an in situ thermolysis cell (Xiamen
University, China) within the temperature range of
setup and experimental conditions.
Figure 2 shows the DSC curves of CL-14 at several
heating rates. We found that the decomposition tempera-
ture of CL-14 shifted to higher temperatures with the
increase in heating rate. The shifts in onset temperature,
peak temperature and end temperature are listed in Table 1.
Interestingly, the heat of decomposition derived from the
exothermic peak area increased with heating rate. These
data are also listed in Table 1 and compared with those of
HMX. Only one decomposition process of CL-14 was
indicated by TG-DSC measurements and DSC curves at
different heating rates.
-
1
20–465 °C and at a heating rate of 10 °C min with a KBr
pellet sample (about 0.7 mg of CL-14 and 150 mg of KBr).
-
1
The IR spectra of CL-14 in the range of 4000–400 cm
were acquired by a model DTGS detector at a rate of
-
1
-1
-1
7
.5 files min and 8 scans file with a resolution of 4 cm
Melting point instrument
The melting point (T ) of CL-14 was measured by WRS-
.
m
From Table 1, we found that the peak temperature of
CL-14 was higher than that of HMX, and the heat of
decomposition of CL-14 was higher by 4–5 times than that
of HMX. The characteristic parameters of thermal
decomposition indicated that CL-14 possessed higher
1
B digital melting point instrument. The sample was dried
at 50 °C for 10 h and filled into the capillary glass tube.
The height of the sample was less than 3 mm. The heating
-
1
rate was 1.5 °C min . The melting point of CL-14 was
determined to be 216.5 °C (489.5 K).
The specific heat capacity
3
2
00
50
–
1
2
0 °C min
The specific heat capacity (C ) of CL-14 was determined
p
–1
by using the continuous mode of the DSC apparatus in the
15 °C min
temperature range of 10–75 °C [24]. The standard molar
200
-
1
-1
K
heat capacity of CL-14 was 1.14 J mol
at 298.15 K.
1
1
50
00
–1
1
0 °C min
Results and discussion
Thermal behavior
5
0
–1
5
°C min
0
–50
The typical TG-DSC curves of CL-14 over the temperature
range of 35–500 °C are shown in Fig. 1. From TG-DSC
curve, only one sharp exothermic peak is observed in the
DSC curve at approximately 301.4 °C, which corresponds
to one-step mass loss of about 81 %. This exothermic
2
60
280
300
320
340
Temperature/°C
Fig. 2 The effect of heating rate on the DSC curves of CL-14 by
DSC instrument
123

X.-L. Fu et al.
Table 1 Characteristic parameters of thermal decomposition for CL-
4 and HMX samples
absorption peaks of CL-14 at the range of 140–350 °C is
shown in Fig. 4.
1
As can be seen in Fig. 4, the intensity of the charac-
teristic absorption peaks of –NH , furoxan ring, –NO and
b/ CL-14
HMX [28]
/°C
-
1
°
C min
-
1
-1
2
2
0
T /°C
T
p
/°C
T
f
/°C
Q
d
/J g
T
p
d
Q /J g
benzene ring decreased with the increase in temperature,
5
1
1
2
297.2 306.2 308.0 4600.4
308.5 312.6 314.8 5128.3
313.0 315.2 317.8 5202.5
314.6 318.0 321.1 5415.8
278.8 1132.1
282.1 1281.1
285.1 1411.7
287.6 1543.3
whereas the absorption peaks of CO at 2400 and
2
-
2280 cm increased as a result of decomposition.
1
0
5
0
Gaseous product analysis by FT-IR
b is the heating rate, T
0
is the onset temperature of the decomposition
is the end
is the heat of
Gaseous products during the thermal decomposition of CL-
14 in the temperature range of 35–380 °C were identified
using FT-IR spectra (shown in Fig. 5). Characteristic peaks
evidently exist in the frequency ranges of 2359, 2286, 2174
reaction, T is the peak temperature in DSC curve, T
p
f
temperature of the thermal decomposition and Q
decomposition
d
-
1
and 1912 cm , which correspond to CO , HNCO, CO and
2
thermal stability than HMX. However, the potential energy
of CL-14 was also considerably higher than that of HMX.
NO, respectively. The relationship between infrared
absorption frequency and gaseous compounds are listed in
Table 3. The FT-IR spectra of CL-14 decomposition gas-
eous compounds in the temperature range of 235–355 °C
are shown in Fig. 6. We can see from Fig. 6 that most of
the gaseous products were produced at approximately
300 °C. Only one decomposition progress occurs in CL-14,
which is in agreement with the study of TG-DSC and DSC
measurements.
Condensed phase compound analysis by RSFT-IR
To investigate the thermal decomposition mechanism of
CL-14, the condensed phase products of CL-14 were
measured by RSFT-IR at different temperatures. The typ-
ical FT-IR spectrum of CL-14 at ambient temperature
(
before heating) is shown in Fig. 3, and the relationship
between infrared absorption frequency and the functional
group of the condensed phase of CL-14 is listed in Table 2.
We can infer from Fig. 3 and Table 2 that the wave
Gaseous product analysis by MS
Figure 7 shows the mass spectra of the main gaseous
products of CL-14. The figure reveals that the mixtures
possess ion current numbers (m/z) of 18, 28, 30, 43 and 44,
among which the ion current intensity of m/z = 30 is the
highest. Based on the literature survey [29–31], several
-
1
number at 3383, 3348, 3270 and 3226 cm
may be
-
1
assigned to –NH , whereas the peak at 1628 cm may be
2
assigned to the furoxan ring. In addition, peaks at 1552 and
-
1
1
1
352 cm may be assigned to –NO , whereas those at
2
-
604, 1510 and 1397 cm may be assigned to the benzene
1
possible species include water (H O = 18), carbon
2
ring. The evident variation in the FT-IR characteristic
monoxide (CO = 28) or nitrogen (N = 28), nitric oxide
2
(NO = 30), cyanic acid (HNCO = 43) and carbon dioxide
(CO = 44). The relative intensity of each pure chemical
2
8
6
4
2
0
0
0
0
0
species obtained by Eq. (1) is summarized in Table 4.
rðiÞ ¼ hðiÞ=RhðiÞ
In the equation, r(i) represents the ratio of the each
species with all chemicals, and h(i) represents the height of
the m/z peak in the mass spectrum of each species.
ð1Þ
In addition, the onset temperature (T ), peak temperature
0
1
552
510
(
T ) and end temperature (T ) detected in the mass spec-
p f
1
trum of CL-14 are also listed in Table 4. As can be seen
from Table 4, the main gaseous products were NO, CO2
3226
270
1397
1226
209
6041295 1250
1500 1000
3
383
1352
3
and H O. The first compound produced at the temperature
2
3
348
1
of 267.4 °C by the decomposition of CL-14 was H O
2
1628
1
(
m/z = 18). This fragment may originate from the con-
4
000
3500
3000
2500
2000
500
cordant reaction, which occurs with the involvement of
NH and NO groups. Then, the compound produced CO,
Wave number/cm–1
2
2
N , NO, HNCO and CO at the temperature range of
2
2
Fig. 3 FT-IR spectrum of condensed phase of CL-14 at ambient
temperature
273.3–299.1 °C.
1
23

Thermal behavior, decomposition mechanism and thermal safety of…
Table 2 The relationship between infrared absorption frequency and functional group of the CL-14 condensed phase
-
1
Function groups
Wavenumbers/cm
Comments
C–NH
C–NO
2
2
3383, 3348
m
m
asNH
2
3
1
270, 3226
295, 1250, 1226, 1209
s 2
NH
mC–N
1552
m
m
asNO
2
1
1
350
s 2
NO
604, 1510
Ring stretching vibration
N
1628, 1510, 1397
Ring stretching vibration
O
N
O
Table 3 The relationship between infrared absorption frequency and
gaseous products
2
2
.2
.0
1
1
1
1
1
0
0
0
0
.8
.6
.4
.2
.0
.8
.6
.4
.2
-
1
Wave number/cm
Gaseous products
CO
2
359
2286
174
1912
2
HNCO
CO
2
NO
0
.0
50
90
3
2
2
30
HNCO
CO2
1
70
0
.05
.04
.03
.02
.01
.00
3
000 2500
2000 1500 1000
500
Wave number/cm–1
0
0
0
0
0
Fig. 4 RSFT-IR characteristic absorption peak intensity of the CL-14
condensed phase at different temperatures
0
.05
CO
NO
235
275
315
355
0
.00
Temperature/°C
Fig. 6 FT-IR absorbance intensity of the decomposition gaseous
products of CL-14 at different temperatures
3
000
300
2
000
200
We inferred from the analysis of the result of RSFT-IR
and TG-DSC-FT-IR-MS that the thermal decomposition
process of CL-14 may be explained by the following
reaction pathway according to experiments and calcula-
tions [32–34].
1
000
100
Fig. 5 FT-IR spectra of decomposition gaseous products of CL-14 at
different temperatures
123

X.-L. Fu et al.
O
NO2
N
H N
2
N
N
N
N
267.4°C
O
+
2H O
2
O
N
N
2
O N
NH
2
N
O
O
O
273.3 – 299.1 °C
CO + N2 + NO + HNCO + CO2 + H O
2
ꢀ
ꢁ
Nonisothermal decomposition kinetics
AE
E
lg b ¼ lg
À 2:315 À 0:4567
ð3Þ
RGðaÞ
RT
To reveal the thermal safety of CL-14, nonisothermal
decomposition kinetics was calculated according to DSC
data at different heating rates. The parameters of the
decomposition kinetics of CL-14 was calculated using
multiple heating methods, including the Kissinger method
-
1
In these equations, b is the heating rate (K min ), T is the
peak temperature in the DSC curve (K), A is the pre-ex-
p
ponential constant, R is the gas constant, E is apparent
-
1
activation energy (kJ mol ), a is the conversion degree,
G(a) is the integral model function and T is the temperature
(K). The kinetic parameter values of the thermal decom-
position reaction of CL-14 as obtained by Eqs. (2) and (3)
are listed in Table 5. In addition to the kinetic parameters
of CL-14, those of ammonium dinitramide (ADN) [37] and
[
Eq. (2)] [35] and the Ozawa method [Eq. (3)] [36].
!
b
AR
¼ ln E
E
ln
À
ð2Þ
2
T
RTp
p
3-nitro-1,2,4-triazol-5-one guanidine salt(GNTO) [38] are
also listed in Table 5 for comparison.
As can be seen from Fig. 2 and Table 2, the peak tem-
perature of CL-14 ranged between 306.2 and 318.0 °C. The
apparent activation energies of CL-14 were 328.7 and
2
1
1
5
.00E–010
.50E–010
.00E–010
.00E–011
-
1
m/z=18
m/z=28
m/z=30
321.8 kJ mol
by Kissinger method and the Ozawa
method, respectively. The thermal stability of CL-14 was
better than those of ADN and GNTO.
Thermal safety
m/z=44
m/z=43
Thermal conductivity
0
.00E+000
Thermal conductivity (k) for the decomposition reaction
could be calculated using the following equation [39]:
À5 3:0116 0:9276
1
60
200
240
280
320
360
400
440
Temperature/°C
3
:7287 Â 10
C
q
Fig. 7 Ion currents of selected ions representing the main evolved
chemical species during thermal decomposition of CL-14
p
k ¼
ð4Þ
À0:7652
M0:2158
T
m
Table 4 Integrated ion current value of MS spectra and chemical composition of gas mixture
Chemical formula
Compounds name
m/z
0
T /°C
p
T /°C
T
f
/°C
Mass/%
H
2
O
Water
18
28
30
43
44
267.4
279.2
273.3
299.1
275.7
306.5
300.2
305.5
299.3
306.8
340.0
319.9
333.8
315.2
323.8
24.0
14.8
33.4
1.0
CO/N
NO
2
Carbon monoxide/nitrogen
Nitric oxide
HNCO
CO
Cyanic acid
2
Carbon dioxide
26.8
1
23

Thermal behavior, decomposition mechanism and thermal safety of…
Table 5 Kinetic parameters of the thermal decomposition reaction of CL-14 and other energetic materials
Explosive
Kissinger
Ozawa
-1
-1
)
-1
-1
)
E/kJ mol
lg(A/s
r
E/kJ mol
lg(A/s
r
CL-14
ADN
328.7
169.6
262.4
27.62
6.31
0.9974
0.9981
0.9849
321.8
–
–
–
–
0.9976
–
GNTO
23.71
258.0
0.9859
In the table, r is the linear correlation coefficient
Table 6 Explosive parameters and comparison of experimental and predicted 50 % drop heights
-
4
-1 -1
K
-3
q/g cm
-1
-1
-1
No.
Explosive
k 9 10 /W m
lg(A/s
)
Q
d
/J g
E/kJ mol
H50/cm
b
T /°C
Exp.
Predicted
1
2
3
4
HMX [28]
GNTO [38]
RDX [29]
CL-14
34.43
–
1.790
–
33.80
23.71
12.50
27.62
2764.2
1026.3
2810.4
5086.3
373.70
262.40
140.00
328.70
32
–
33.40
–
279.9
256.3
10.58
35.20
1.660
1.932
26
20.10
39.79
307.9
-
1
-1
where C is the specific heat capacity (J g
-
K
), q is the
density of CL-14 (g cm ), T is the melting point (K) and
where E is apparent activation energy obtained by Ozawa
0
p
3
-1
method (kJ mol ), R is the gas constant (J mol
-1 -1
K )
m
M is the molecular weight of CL-14.
and Te0 is the onset temperature (K).
-
1
-1
-1
By substituting the values of C = 1.14 J g
p
K
,
By substituting the values of E = 321.8 kJ mol
0
,
-
3
-1 -1
K
T = 489.5 K, M = 256 and q = 1.932 g cm [27] into
R = 8.314 J mol
and Te0 = 572.2 K into Eq. (7),
m
-
4
-1 -1
Eq. (4), the value of k (k = 35.2 9 10 W m
was obtained.
K
)
we obtain the value of T of 307.9 °C.
b
Characteristic drop height of impact sensitivity
Self-accelerating decomposition temperature
The impact sensitivity is an important parameter for eval-
uating the security and reliability of EMs and can be
characterized by 50 % drop height (H ). The characteristic
The value (T ) of the onset temperature (T ) corresponding
e0
e
to b ? 0 was obtained by Eq. (5), and the self-accelerating
decomposition temperature (TSADT) obtained by Eq. (6)
was 282.0 °C for CL-14 [40]:
5
0
drop height for impact sensitivity (H ) for the decompo-
50
sition reaction can be calculated using Eq. (8) [43]:
sffiffiffiffiffiffiffiffiffiffiffi
2
i
3
i
Tei ¼ Te0 þ bb þ cb þ db i ¼ 1; 2; 3; 4
ð5Þ
i
1
2
k
0:02612E
n lg H50 þ lg
þ D þ
¼ 0
ð8Þ
3
n
50
AqQd
T1 þ D2H
where b, c and d are coefficients, and b is the heating rate
-
K min ).
1
(
where n, D and D are parameters of the correlation, k is
2
3
-
1 -1
K ), A is the pre-exponen-
TSADT ¼ Te0
ð6Þ
thermal conductivity (W m
-
3
tial constant, q is the density of CL-14 (g cm ), Q is the
d
-
heat of decomposition (J g ) and E is apparent activation
1
Critical temperature of thermal explosion
-1
energy obtained by Kissinger method (kJ mol ).
The
corresponding
values
of
n = 0.564623,
The critical temperature of thermal explosion (T ) is an
b
D = 33.8765 and D = –0.347174 are obtained in the lit-
2
3
important parameter for energetic materials to ensure safe
storage and operations when used in propellants, explo-
sives and pyrotechnics. Equation (7) was used to obtain the
erature [44]. By substituting the values of k = 35.2 9
-4
-1 -1
-3
27.62 -1
s ,
1
0
W m
K
, q = 1.932 g cm , A = 10
Q = 5086.3 J g and E = 328.7 kJ mol into Eq. (8),
-1
-1
d
value of T for CL-14 [41, 42].
b
the H50 value of 39.79 cm was obtained. The characteristic
drop height of impact sensitivity and the critical temperature
of thermal explosion of CL-14, GNTO, HMX and RDX are
pffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi
2
0
E0 À E À 4E RT
0
e0
Tb ¼
ð7Þ
2
R
123

X.-L. Fu et al.
listed in Table 3 to compare the thermal stability of energetic
materials.
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9
. Bogdanova YA, Gubin S, Korsunskii B, Pepekin V. Detonation
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temperature is Tb(CL-14) = 307.9 °C [ Tb(HMX) = 279.9 °C
[
Tb(GNTO) = 256.3 °C, whereas the order of the character-
istic drop height of impact sensitivity is H50(CL-14)
9.79 cm[ H50(HMX) = 33.4 cm[ H50(RDX) = 20.1 cm.
1
0. Badgujar D, Talawar M, Asthana S, Mahulikar P. Advances in
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=
3
The results indicated that CL-14 possesses an insensitive
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2
2
2
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123