fox-7, an im ingredient candidate – where are we today? · 2009 insensitive munitions and...

2009 Insensitive Munitions and Energetic Materials Technology Symposium

FOX-7, an IM Ingredient Candidate – Where Are We Today?

FOX-7, an IM Ingredient Candidate – Where Are We Today?

Helena Bergman, Anna Pettersson and Henric Östmark,Swedish Defence Research Agency, FOI

Helen Stenmark and Carina Bergvall-LaitalaEurenco Bofors AB

Helena Bergman, Anna Pettersson and Henric Östmark,Swedish Defence Research Agency, FOI

Helen Stenmark and Carina Bergvall-LaitalaEurenco Bofors AB


OutlineOutlineWhy new Energetic MoleculesFOX-7 BasicsFOX-7 CrystalsFOX-7 Formulations and ApplicationsConclusions

Why new Energetic MoleculesFOX-7 BasicsFOX-7 CrystalsFOX-7 Formulations and ApplicationsConclusions


Ways to Insensitive Munitions..Ways to Insensitive Munitions..Modify the energetic material Modify the composition Modify the munition

Modify the packagingModify the ammunition depot or storage


Ways to Insensitive Munitions..Ways to Insensitive Munitions..Modify the energetic material Modify the composition Modify the munition

Modify the packagingModify the ammunition depot or storage

FOI activities


FOX-7FOX-71,1-Diamino-2,2-dinitroethyleneDeveloped at FOI in 1997--WO Patent No. 9903818Produced by EURENCO Bofors AB under licence by Swedish Government

1,1-Diamino-2,2-dinitroethyleneDeveloped at FOI in 1997--WO Patent No. 9903818Produced by EURENCO Bofors AB under licence by Swedish Government

HNO3/H2SO45-10oC

H+, H2O

H2N

H2N

NO2

NO2

88%

N NH

O O

HN NH

O O

O2N NO2

O2N NO2

FOX-7 BasicsFOX-7 BasicsLow sensitivity explosivesSimple synthesis

Low sensitivity explosivesSimple synthesis

Density (crist): 1.885 g/cm3

Heat of Formation: -32 kcal/moleSensitivity: drop weight 70 cm

(RDX 38 cm)

friction > 350 N

(RDX 120 N)

Explosion Temperature: 215 oC

(RDX 220 oC)

Detonation Pressure (calc): 33.96 GPa

(RDX 34.63 GPa)

Detonation Velocity (meas.): 8870

m/s

(RDX 8930 m/s)

H2N

H2N

NO2

NO2

N NH HN NH

O2N NO2

OO2N NO2

HNO3/H2SO4 aq NH3

SynthesisSynthesis

Crystal StructureCrystal Structure

FOX-7

Impact and Friction Sensitivity of FOX-7Impact and Friction Sensitivity of FOX-7

Sample Drop height (cm)

Friction (N)

FOX-7 (recryst., 250–355 μm) 79

FOX-7 (recryst., < 70 μm) 63 >340

RDX 38 126

FOX-7: DSCFOX-7: DSC

Temperature (oC)100 150 200 250 300 350

Hea

t Flo

w (

W)

0

10

20

30

40

50

60

1000/T1.94 1.96 1.98 2.00 2.02 2.04

ln (R

)

-1

0

1

2

3Ea

=234

kJ/mole (56

kcal/mole)

FOX-7: SSGTFOX-7: SSGT

Acceptor (FOX-7)

Donor (RDX 98/1/1)

Attenuator (PMMA)

Witnessblock

HolderDetonator

12.7 mm

38.1 mm

3.59 - 12.73 mm

38.1 mm

38.1 mm

76.2 mm

25.4 mm

5.11 mm

EXPLOSIVE DENSITY(g/cc)

AttenuatorThickness

(mm)Tetryl 1.65 8.36

HNS II 1.635 7.19

TNT 0.92*TMD 6.4

HMX 0.92*TMD 10.3RDX 0.92*TMD 9.33FOX-7 1.634 6.22


FOX-7FOX-7Small-scale gap test

Air gap test

Small-scale gap test

Air gap testName Density Distance

(50% probability point)

TNT 1.51 g/cm3 (91% of TMD) 34 –

35 mm

FOX-7 1.72 g/cm3 (91% of TMD) 35 –

37.5 mm

Composition B 1.59 g/cm3 (91% of TMD) 60 –

62.5 mm

H. Östmark et al. Int. Det. Symp. (1998)R. Adolfsson et al. FOI-R-0668-SE (2003)

Name Density Distance

(50% probability point)

FOX-7 1.63 g/cm3 (86% of TMD) 6.2 mm

TNT 1.53 g/cm3

(92% of TMD) 6.4 mm

RDX 1.66 g/cm3

(92% of TMD) 9.3 mm

FOX-7: Ignition Temperature (Wood’s metal bath)

FOX-7: Ignition Temperature (Wood’s metal bath)

Temperature of metal bath [ C]

210 220 230 240 250 260 270

Tim

e to

reac

tion

[s]

0

50

100

150

200

250

No reaction when T < 215oC(RDX ignites at 220°C)

FOX-7: KOENEN TEST (Steel sleeve test)

FOX-7: KOENEN TEST (Steel sleeve test)

Type “F”

reaction at nozzle plate diameter 6 mmRDX explodes at nozzle plate diameter 8 mm

FOX-7: Compatibility by HFCFOX-7: Compatibility by HFCPolymer Ea (J/g/week) Cab (J/g/week)CAB (BF900) 0.38 -0.38 Estane 0.27 -0.26 GAP (SNPE) 2.57 -0.44 HTPB (R-45 HT) 1.89 3.89 HTPB (Krasol LBH) 0.24 0.13 Viton 0.10 0.03 Isocyanate H12MDI 0.70 0.41 Plasticizer Butyl-NENA 1.07 0.16 K-10 0.41 0.44

2ba

ababEEEC

Incompatible:C>20 J/g/week

Slightly Incompatible:10 J/g/week

<C<20J/g/week

Compatible:C<10 J/g/week


FOX-7 Cylinder testsFOX-7 Cylinder tests

detail image

Pcj (Gpa)

E0 (kJ/cc)

A (Gpa)

B (Gpa)

R1 R2 w

27.9 8.663 998.6 8.78 4.93 1.12 0.40

Data for FOX-7 + 1.5 w% wax, δ

= 1.756 g/cc The detonation velocity was estimated to 8.335 ±

0.025 mm/μs;

A Cheetah calculation, BKWC, gave a velocity of 8.266 mm/μs, which is in good agreement with the experimental value.


FOX-7FOX-7

Candidate for ingridients in BoostersShape Charge warheadsHigh performance warheadsRocket and gun propellants

Particle size and particle quallity is very important for sensitivity and processing properties

Candidate for ingridients in BoostersShape Charge warheadsHigh performance warheadsRocket and gun propellants

Particle size and particle quallity is very important for sensitivity and processing properties

250 µm250 µm250 µm250 µm


NSF 110 (20 –

40 µm) is the smallest particle size available which also gives a relatively low bulk density, < 0.6 g/cm3 according to Hall measurements. Below, a SEM-photo with a1000 times magnification is shown together with a particle size distribution measured by Malvern is shown.


NSF 120 (50 –

100 µm) gives a bulk density of approximately 0.7 g/cm3 according to Hall. The picture shows a 200 times magnification of the particles and a particle size distribution measured by Malvern.


NSF 130 (100 –

200 µm) gives a bulk density of approximately 0.85 g/cm3. The SEM photo is a 70 times magnification and the particle size distribution is a Malvern measurement.


0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

04 35 739

04 36 753

08 07 038

>75µ

150-75µm

300-150 µm

>300µm

NSF 140 (250 –

350 µm) is the largest particle size available at present. This quality has a bulk density of approximately 0.95 according to Hall. The SEM photograph is 70 times magnification and sieving results for a couple of batches are shown a long side.


•

Eurenco Bofors AB has produced nerly 1000 kg (7 kg batches, 1 to 3per day) of FOX-7 in its own pilot plant

•

Molar yield 80 % for nitration step•

Very small particle size has caused problems to wash the filter cake. A separate washing step has been introduced to obtain pure product

•

HPLC-purity is more than 99 % for washed product

•

Eurenco Bofors AB has produced nerly 1000 kg (7 kg batches, 1 to 3per day) of FOX-7 in its own pilot plant

•

Molar yield 80 % for nitration step•

Very small particle size has caused problems to wash the filter cake. A separate washing step has been introduced to obtain pure product

•

HPLC-purity is more than 99 % for washed product

Scaling up of FOXScaling up of FOX--77


Insensitive Formulations and Applications

Insensitive Formulations and Applications

Pressed ExplosivesPressed ExplosivesPressed FOX-7/wax (97.8/2.2 wt%)Investigated as an explosive for use in shape charge applications

Pressed FOX-7/wax (97.8/2.2 wt%)Investigated as an explosive for use in shape charge applications

A. Helte et al. 23rd Int Symp on Ballistics, Spain

(2006)A. Helte et al. FOI-R-1780-SE

(2005)

Pressed ExplosivesPressed Explosives

Jet straightness

Jet velocity

Fragmentation timeFOX-7 > Comp B

Jet straightness

Jet velocity

Fragmentation timeFOX-7 > Comp B

Penetration (ARMOX 300S)FOX-7 230 mm (2.9 cal) Comp B 265 mm (3.3 cal)

Penetration (ARMOX 300S)FOX-7 230 mm (2.9 cal) Comp B 265 mm (3.3 cal)

A. Helte et al. 23rd Int Symp on Ballistics, Spain

(2006)A. Helte et al. FOI-R-1780-SE (2005)


FOF-2FOF-2FOX7 (255-350mm)

50 wt%

FOX7 (< 70mm)

20 wt%PolyGlyN

21wt%

Butyl-NENA

5 wt%H12MDI (Desmodur-W)

4 wt%

DBTDL

0.03 wt%

Tg = -35°CThermally stable at 65°C (14 days)

FOX7 (255-350mm)

50 wt%FOX7 (< 70mm)

20 wt%

PolyGlyN

21wt%Butyl-NENA

5 wt%

H12MDI (Desmodur-W)

4 wt%DBTDL

0.03 wt%

Tg = -35°CThermally stable at 65°C (14 days)

Small-scale slow cook-offSmall-scale slow cook-off

100100--400400°°CCHeating rate: 3.3Heating rate: 3.3°°C/hourC/hour

RDX/TNT 60/40RDX/TNT 60/40

TTcookcook--offoff

207207°°C (Type I reaction)C (Type I reaction)

FOFFOF--22

TTcookcook--offoff

220220°°C (Type V reaction)C (Type V reaction)

Small-scale slow cook-off -

ResultsSmall-scale slow cook-off -

Results


A New Explosives Formulation -

FOF-5A New Explosives Formulation -

FOF-5

FOX-7 (238µm)

38.1 %FOX-7 (32µm)

25.4 %HMX (22 µm)

16.5 %Energetic binder

20%PolyGlyN

7.2 %GAP 7.2 %Butyl-NENA

3.6 %H12

MDI (Desmodur-W)

2.0 %DBTDL

FOX-7 (238µm)

38.1 %FOX-7 (32µm)

25.4 %HMX (22 µm)

16.5 %Energetic binder

20%PolyGlyN

7.2 %GAP 7.2 %Butyl-NENA

3.6 %H12

MDI (Desmodur-W)

2.0 %DBTDL

Slow Heating (Slow Cook-Off)Slow Heating (Slow Cook-Off)

First test (inert fuze)

Type V response (fire)

Second test (HNS II-based fuze)

Type IV response (deflagration)

Composition B Type I response (detonation)

First test (inert fuze)


Second test (HNS II-based fuze)

Type IV response (deflagration)Composition B Type I response (detonation)

Fast Heating/Fuel Fire (Fast Cook-Off)Fast Heating/Fuel Fire (Fast Cook-Off)

Blast pressure (max 160 Pa) and no significant heat radiation

Type IV response (fire)

Debris (fuze) recovered at > 24 meters from test stand



Blast pressure (max 160 Pa) and no significant heat radiation

Type IV response (fire)

Debris (fuze) recovered at > 24 meters from test stand



Bullet ImpactBullet Impact

Debris (fuze) recovered less than 15 meters from test stand



Debris (fuze) recovered less than 15 meters from test stand



A Potential IM Explosive?A Potential IM Explosive?•

FOF-5 is a cast-cured explosive based on FOX-7 and HMX with the same performance (calc.) as Composition B (RDX/TNT 60/40).

•

Initial IM testing of ammunition containing FOF-5 -

results:

•

FOF-5 is a cast-cured explosive based on FOX-7 and HMX with the same performance (calc.) as Composition B (RDX/TNT 60/40).

•

Initial IM testing of ammunition containing FOF-5 -

results:

Slow Cook-Off Fast Cook-Off Bullet ImpactFOF-5(Batch No. 1)

Fire (1st test)Fire/Defl (2nd test)

Deflagration Fire

Composition B Detonation Detonation Detonation


Composite propellantsComposite propellantsFOX-12/RDX and FOX-7/HMX based compositions

Energetic binder

FOX-12/RDX and FOX-7/HMX based compositionsEnergetic binder

Temperature (K)

2000 2200 2400 2600 2800 3000 3200 3400

Forc

e (J

/g)

800

850

900

950

1000

1050

1100

1150

1200

FOX-7 based propellantFOX-12 based propellant

Pressure (MPa)

20 40 60 80 200 40010 100

Burn

rate

(mm

/s)

20

40

60

80

200

400

600

10

100

FOX-12 based propellantJA 2XM 39

y=0.81P0.90

( )

y = 0.09P1.32

y = 3.82P0.73


N

NO2

NO2

H2N N NH2

O

H

NH2-+

H2N NO2

NO2H2N

NO2

NH2

NO2

NH2

H2N

O2N

N

N

NO2

O

O2N

NH2H2N

N

N

N

H

NO2

H

O

Low Sensitivity Explosives HELow Sensitivity Explosives HE

TATB

LLM-105

NTO FOX-7

FOX-12


ConclusionsConclusionsFOX-7 is very insensitive. FOX-7 makes it possible to produces low sensitivity

charges with high performance, as

exemplified by the shaped charge and 40mm small caliber examples. The availability of more and better characterized particle sizes will enable an easier development of new low sensitivity, high performance applications.

FOX-7 is available in large quantities

FOX-7 is very insensitive. FOX-7 makes it possible to produces low sensitivity

charges with high performance, as

exemplified by the shaped charge and 40mm small caliber examples. The availability of more and better characterized particle sizes will enable an easier development of new low sensitivity, high performance applications.FOX-7 is available in large quantities

fox-7, an im ingredient candidate – where are we today? · 2009 insensitive munitions and...

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