Estimation of Life Assessment of Energetic Materials
using Advanced Kinetic Elaboration of HFC Signals
B. Roduit (1), P. Guillaume (2), S. Wilker (3), P. Folly (4), A. Sarbach (4), B. Berger (4),
J. Mathieu (4), M. Ramin (5), B. Vogelsanger (5)
AKTS AG, http://www.akts.com, TECHNOArk 3, 3960 Siders, Switzerland
PB Clermont s.a., http://www.pbclermont.be, Rue de Clermont 176, 4480 Engis, Belgium
(3) Bundeswehr Institute for Materials (WIWEB), Grosses Cent, 53913 Swisttal-Heimerzheim, Germany
(4) armasuisse, Science and Technology, http://www.armasuisse.ch, 3602 Thun, Switzerland
(5) Nitrochemie Wimmis AG, http://www.nitrochemie.com, 3752 Wimmis, Switzerland
(1)
(2)
ESTAC - 10
22 - 27 August 2010
Rotterdam – The Netherlands
www.armasuisse.ch
www.nitrochemie.com
www.akts.com
www.pbclermont.be
www.bwb.org
1
DSC
TG
The precise prediction of the degradation of materials
HPLC
HFC
CL
2
Exo
TG
DSC
HeatFlow (W/g)
8
6
4
Heat : -121.682 (J/g)
2
0
-2
150
160
.
170
180 190 200
Temperature (°C)
210
220
230
The precise prediction of the degradation of materials
HPLC
HFC
CL
3
More precise measurement
of the
thermal aging
of
energetic materials
-Applications of
isothermal microcalorimetry
(HFC)
4
Exo
TG
DSC
HeatFlow (W/g)
8
6
4
Heat : -121.682 (J/g)
2
0
-2
150
160
.
170
180 190 200
Temperature (°C)
210
220
230
The precise prediction of the degradation of materials
HPLC
HFC
CL
5
Exo
TG
HeatFlow (W/g)
8
6
4
DSC
Heat : -121.682 (J/g)
2
0
-2
150
.
160
170
180 190 200
Temperature (°C)
210
220
230
The precise prediction of the degradation of materials
HPLC
CL
6
Experimentally :
Just few temperatures
7
reaction progress
APPLICATION OF HFC
The use of HFC enables to gain advanced
knowledge on the reaction rate at the early stage
of the decomposition
experiments
?
0%<a<5%
temperature
T1
T2
T3
predictions time
50°C < T < 100°C
days < t < months
8
Reaction
rate
Well
defined
50°C
Reaction
progress
Because baseline is well defined
Well
defined
7 years !
9
Isoconversional methods
Uncertainity of thermokinetic analysis : the stages and
physico-chemical reaction pathways are generally unknown
2.75
Exo
?
2.5
2.25
2
HeatFlow |-bs (W/g)
What do you see below?
Young women? Old man?
Or both?
1.75
1.5
1.25
1
0.75
0.5
0.25
0
200
220
3-Methyl-4-nitrophenol_DSC_dyn_2G
240
260
Temperature (°C)
280
300
Observed thermal event can be the sum of
thermal events created during certain stages
of the reaction which are not always known
10
Isoconversional method
Isoconversional methods (model free):




Three main modifications of isoconversional method are applied in the literature:
- Differential (Friedman)
- Integral (Flynn-Ozawa-Wall)
- Advanced integral based on non-linear procedure (Vyazovkin)
Differential isoconversional method
Reaction rate expressed by the Arrhenius equation
=

Reaction rate
at a given reaction progress a
is only a function of the temperature
A’(a) and E(a) are the pre-exponential factor and apparent activation energy
11
activation energy E /kJ·mol^-1
Activation energy E as a function of the heat release
160
A
150
140
Ea = 138 kJ/mol
130
120
110
100
0.1
1
10
heat release Q /J·g^-1
100
1000
12
THERMAL
AGING
heat flow /W·g^-1
1.E-03
Ia
89°C
80°C
1.E-04
70°C
1.E-05
60°C
50°C
1.E-06
40°C
1.E-07
30°C
1.E-08
10°C
1.E-09
0.0001
0.001
0.01
0.1
time /year
1
10
20°C
100
13
THERMAL
AGING
heat release /J·g^-1
1000
Ib
89°C
100
80°C
70°C
60°C
50°C
40°C
30°C
10
20°C
10°C
1
0.1
0.01
0.001
0.01
0.1
1
10
100
time /year
14
Beijing
60
temperature /°C
50
40
30
20
STANAG 2895
A2 (Hot dry)
10
0
0
2
4
6
8
10
time /year
15
=
The assumption that
the reaction rate da/dt
at a given reaction progress a
is only a function of the temperature
(differential isoconversional analysis)
is acceptable.
It can be applied for a precise life assessment of energetic materials16
Conclusion
(a ± 0.1%)
very precise predictions
long term predictions
fast experiments
(<10 hours)
?
Exo
HeatFlow (W/g)
8
6
4
(>1 year)
Heat : -121.682 (J/g)
2
0
-2
150
.
160
170
180 190 200
Temperature (°C)
DSC
210
220
230
HFC
17
Conclusion
(a ± 0.1%)
very precise predictions
fast experiments
(<10 hours)
long term predictions
(>1 year)
If you want to perform fast experiments (DSC) and get long term predictions using
thermokinetics do not expect very precise predictions.
If you want to perform fast experiments (DSC) and get very precise predictions using
thermokinetics do not expect long term predictions.
If you want to achieve long term predictions and expect very precise predictions using
thermokinetics do not perform fast experiments (DSC). Do long term isothermal
microcalorimetric measurements (HFC) and perform thermokinetics.
18
Conclusion
(a ± 0.1%)
very precise predictions
long term predictions
fast experiments
(<10 hours)
?
Exo
HeatFlow (W/g)
8
6
4
(>1 year)
Heat : -121.682 (J/g)
2
0
-2
150
.
160
170
180 190 200
Temperature (°C)
DSC
210
220
230
HFC
19
Acknowledgements
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20
Advanced Kinetics and Technology Solutions