Development Of A Pvdf Based Sensor

1. Development of a PVDF based
sensor
Universite de Haute-Alsace
ENSITM
Nuno Pimenta

2. Objectives
 Development of a sensor
 Rheological characteristics
 Spinning a filament with a diameter
of 200µm
 Physical characteristics

3. Polyvinylidene fluoride (PVDF)
 Piezo, pyroelectric
properties.
 α, β, γ and δ.
 Applications such
as sensors of
pressure, heat, etc.

4. Polyvinylidene fluoride (PVDF)
 The vinylidene
fluoride monomer
 Properties:
– mechanical
– Thermal
– Electrical
– Chemical
resistance

5. Molecular structure
 α and β phases
 Linear polymer
− Two dipole
moments
− CF2
− CH2
 Electronegativety
difference in PVDF

6. α and β phases
 α phase
– Non polar
 β phase
– Highly polar
 Polarization
– Dipole moments
are randomly
oriented
– Application of an
electrical field

7. PVDF-TrFE copolymers
 Copolymers formed by vinylidene
fluoride and trifluoroethylene
– Higher temperatures
– New sensor shapes
– Higher level of piezoelectricity
– Does not require stretching
– Crystallize directly in a polar phase
(similiar to β phase of PVDF)

8. PVDF-TrFE polarization
 PVDF-TrFE require
only temperature
and an electrical
field

9. PVDF spinning
 Typical process:
− Extrusion of the
molten polymer
− Stretching
− Cooling
− Winding the Filament of
filament cupper
 Insertion of a
filament (cupper)

10. The different stages of the project
Rheological properties
Filament spinning
Physical properties
Insertion of cupper
filament

11. Results
 Rheological tests
– Viscosity curves
– Dynamic curves
– Viscosity in function of time
 Spinning tests
 Physical tests

12. Rheological tests
 Viscosity curves
10000
8000
6000 pvdf flow (230°c)
pvdf flow (240°C)
pvdf flow (250°C)
4000
pvdf flow (260°C)
pvdf flow (270°C)
2000 pvdf flow (295°C)
0
0,001 0,01 0,1 1 10 100 1000
-2000

13. Rheological tests
 Dynamic curves
3,50E+05
3,00E+05
2,50E+05
pvdf (250°C, 10%)
2,00E+05 storage
1,50E+05 pvdf(250°C, 10%)
loss
1,00E+05
5,00E+04
0,00E+00
0 200 400 600 800

14. Rheological tests
 Dynamic curves
3,00E+05
2,50E+05
2,00E+05
pvdf (260°C, 10%)
storage
1,50E+05
pvdf(260°C, 10%)
1,00E+05 loss
5,00E+04
0,00E+00
0 200 400 600 800

15. Rheological tests
 Dynamic curves
3,00E+05
2,50E+05
2,00E+05 pvdf (270°c, 10%)
storage
1,50E+05
pvdf (270°C, 10%)
1,00E+05 loss
5,00E+04
0,00E+00
0 200 400 600 800

16. Rheological tests
 Viscosity in
function of time
pvdf (200 pa)
4400
4300
4200
4100 pvdf (200 pa)
4000
3900
3800
0 5 10 15 20 25 30 35

17. Rheological tests
 Viscosity in function of time
pvdf (300 pa)
4800
4700
4600
4500
pvdf (250 pa)
4400
4300
4200
4100
0 10 20 30 40

18. Spinning tests
 Spinneret 1mm
250
200
250 500
diameter
150
250 300
240 300
100
270 500
50
0
13
15
17
19
21
23
25
27
29
11
1
3
5
7
9
samples

19. Spinning tests
 Spinneret 2mm, winding velocity
300rpm
300
250 1
2
200 3
diameter
4
150
5
100 6
7
50
8
0 9
10
13
15
17
19
21
27
29
11
23
25
1
3
5
7
9
samples

20. Spinning tests
 Spinneret 2mm, winding velocity
280rpm
300
250
200
diameter
150
100
50
0
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29
samples

21. Physical tests
 Test 1
1200 4
3,5
1000
3
800
MODULE
2,5
FORCE
600 2
400 1,5
1
200
0,5
0 0
190 180 250 200 220 200 230 210 230 220 190 180 250 200 220 200 230 210 230 220
DIAMETER DIAMETER

22. Physical tests
 Test 2
1200 4,5
4
1000
3,5
800 3
MODULE
FORCE
2,5
600
2
400 1,5
1
200
0,5
0 0
200 190 200 210 220 180 230 180 200 220 200 190 200 210 220 180 230 180 200 220
DIAMETER DIAMETER

23. Physical tests
 Test 3
1200 4
1000 3,8
800 3,6
MODULE
FORCE
600 3,4
400 3,2
200 3
2,8
0
200 240 190 230 210 180 230 170 230 210 200 240 190 230 210 180 230 170 230 210
DIAMETER DIAMETER

24. Physical tests
 Test 4
1800 4,5
1600 4
1400 3,5
1200 3
MODULE
FORCE
1000 2,5
800 2
600 1,5
400 1
200 0,5
0 0
230 180 180 160 230 240 190 170 150 180 230 180 180 160 230 240 190 170 150 180
DIAMETER DIAMETER

25.  Physical properties for PVDF-TrFE
Properties PVDF-TrFE
Elongation (%) 29,95
Module (MPa) 917,47
Force (N) 3,26
Diameter (µm) 204

26. Conclusion
 Rheolgical characteristics
− Viscosity
 Spinning
− diameter of the filament was succesfully
obtained (200µm)
− big variations in diameter
→ modification of the cooling system
 Physical properties
− good elongation
 Development of a PVDF based sensor

27. References
 H. Kawai, The piezoelectricity of poly(vinylidene fluoride), J. Applied Phys. 8, pp 975, (1969).
 R. Barbosa, J.A. Mendes, V. Sencadas, J.F. Mano, and S.Lanceros-Mendez, Chain reorientation in β-PVDF films upon
transverse mechanical deformation studied by SEM and dielectric relaxation,Ferroelectrics, 294, pp 73-83, 2003
 F.Bauer, H.Moulard, G.Samara, Advances in ferroelectric polymers for shock compression sensors, American Institute
of Physics, 1970
 Feng Xia, Hengfeng Li, Cheng Huang, M.Y.M.Huang, H. Xu, Francois Bauer, Z.Y.Cheng, Q.M.Zhang, Poly(vinylidene
fluoride-trifluoroethylene) based high performance electroactive polymers, Smart structures and materials 2003, 3-6
March, 2003
 W.Eisenmenger, H.Schmidt and B.Dehlen, Space charge and dipoles in Polyvinylidene, Brazilian Journal of Physics, vol.
29, 2, June 1999
 Larissa Pinheiro, Matheus Chaud, Pedro Nascente and Rinaldo Gregorio Jr, Morphology of PVDF, P(VDF-TrFE)
copolymers and PVDF/P(VDF-TrFE) blends, Acta Microscopica, vol. 12, 1, December, 2003
 F. Bauer, Properties of ferroelectric polymers under high prssure and shock loading, Institute Franco-Allemand de
Recherches
 Francois Bauer, PVDF shock sensors: Applications to polar materials and high explosives, IEEE transactions of
ultrasonics, Ferroelectrics and frequency control, vol. 47, 6, November 2000
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 Lee Keun Yoon, Byung Kyu Kim, Compatibility of Poly(vinylidene fluoride) (PVDF)/ Polyamide 12(PA12) blends, Journal
of Applied Polymer Science, vol. 78, pp 1374-1380, 2000
 T.Koizumi, S. Usui, The dependence of shear and elongational viscosity on the molecular weight of Poly(vinylidene
fluoride), Journal of Applied Polymer Science, vol.71, 2381-2384, 1999
 Measurement specialties, Inc., Piezo film sensors technical manual