Platzhalter Titelbild Superabsorbent Polymers (SAP) as Water-Blocking Components in Cables Martin Tennie ([email protected]) ICC Meeting November

Platzhalter Titelbild

Superabsorbent Polymers (SAP) as Water-Blocking Components in Cables

Martin Tennie ([email protected])ICC Meeting November 2012St.Petersburg, Florida, USA

Martin TennieICC Meeting Nov.2012, St. Petersburg, Florida

Modern Superabsorbents

Seite | 2


Modern Superabsorbents

Seite | 3

SAP is a crosslinked and partely neutralized (mostely with Sodium) poly-Acrylic-Acid forming a 3-dimensional network

COO Na

COO Na

COOH

COOH

COO Na

COO Na

COOH

COO Na

COO Na

COOH COO Na

COO NaCOO Na

COO Na

Na OOCHOOC

Na OOC

Na OOC

HOOC


Polymerisation

Seite | 4

Radical Chain Polymerisation

I-CH2-CH-CH2-CH-COOH

COOH

I-CH2-CH-COOH

I + CH2=CH-COOH

I-CH2-CH-COOH + CH2=CH-COOH

I : Radicalic Starter

I-CH2-CH-CH2-CH-COOH

COOH

+ CH2=CH-COOH I-CH2-CH-CH2-CH-CH2-CH

COOH COOH COOH


Crosslinking

Seite | 5

Time

Temp.

Time

Temp.

Time

Temp.

I-CH2-CH-CH2-CH-CH2-CH

COOH

COOH

COOH

- II

I

I

Short chains„Extractables“


Polymerdesign and Properties

Seite | 6

Absorption/Retention: Funktion of cross-linking

Retention /Absorption

Degree of crosslinking(crosslinker/ monomer ratio)

High retention capacity



Seite | 7

Elasic Modulus: Funktion of cross-linking

Gel Strength /Absorptionunder load

Degree of crosslinkingSoft swollen gelEasily deformed

High gel strength SAPNot easily deformed



Seite | 8

Absorption speed: Function of elasticity (cross-linking) and particle size

Small particle large outer surface

Large particle small surface area

Relaxing force vs swelling forceSwelling Force

Relaxing Force


Hydrolysis Stability

Seite | 9

Turning from a particle of hydrogel into a viscous liquid

Energy/Water Energy/Water

Breaking the x-linking Breaking the chains


Product Properties

Seite | 10

Absorption Speed

Absorption/RetentionHydrolysis Stability

“Gelstrength”Elastic Modulus

Water Conductivity “Permeability”


Core Property - Permeability

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Permeability means water transport through a mass of swollen SAP

High permeability Low Permeability


Influencing the Permeability

Seite | 12

Particle shape


Influencing the Permeability

Seite | 13

Extractables:

Short to mid chain length and not incorporated to the network and water soluble.

Acting as thickener and increase the viscosity of water.

Darcy´s Law:

LP

dtdv AD

= Pressure difference driving the permeation

D = Specific permeability of sample

APL

= Cross-sectional area of sample

= Length of sample

= Viscosity of fluid


Tested SAP Materials

Seite | 14

Sample Code

1 2 3 4 5 6

Morphology Bead Bead Bead Crystal Crystal Crystal

Absorption in DI Water [g/g]

460 440 380 260 200 210

Absorption Speed [mm after 1 min.]

> 16 > 16 16 12 3 7


Gel Degradation at 80 °C

Seite | 15

Degradation of hydrogel made with DI-water(x-axis not linear)



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Degradation of hydrogel made with Synthetic Sea Water (DIN 50900)(x-axis not linear)



Seite | 17

Degradation of hydrogel made with hard tap-water (Grade4) (x-axis not linear)


Gel Degradation

Seite | 18

What the numbers mean in reality – A non stable product


Gel Degradation

Seite | 19

What the numbers mean in reality – A non stable product

3 weeks later


Gel Degradation

Seite | 20

What the numbers mean in reality– A non stable product


Gel Degradation

Seite | 21

What the numbers mean in reality – A stable product


Gel Degradation

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What the numbers mean in reality – A stable product

3 weeks later


Gel Degradation

Seite | 23

What the numbers mean in reality– A stable product


Rheological Properties

Seite | 24

0

2

4

6

8

10

12

#1 #2 #3 #4 #5 #6

Sample

Vis

cosi

ty/G

elst

ren

gth

[[l

og

Pa]

Quarter Saturated

Half Saturated

Full Saturated

Correlation E-modulus and degree of saturation (DI-water)


Rheological Properties

Seite | 25

0

1

2

3

4

5

6

7

#1 #2 #3 #4 #5 #6

Sample

Gel

stre

ng

th [

Pa]

Gelstrength of 100% saturated (DI-water) SAP


Permeability Determination

Seite | 26

Shematic and real set-up of test equipment



Seite | 27

Picture of a treated capillary.

The red lines indicates the measured penetration distance.



Seite | 28

Time Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 Sample 6Minutes

5 1 1 4 1 1 210 2 2 4 1 1 220 2 2 4 1 1 260 2 2 4 2 2 2

120 2 3 4 2 2 2480 3 3 4 3 3 2

Days 1 6 9 6 4 5 52 8 14 8 6 8 73 10 18 11 8 10 84 12 20 12 9 11 85 15 23 13 10 12 106 18 24 14 12 14 117 30 36 16 13 15 11

Density [g/g]

365 375 385 380 360 385

DI Water at 20 °C



Seite | 29

DI-Water at 60 °C


5 0 0 0 0 1 110 0 0 1 1 1 220 0 1 2 1 2 260 1 1 2 1 2 2

120 1 1 4 2 2 3480 2 1 6 3 4 3

Days 1 4 3 8 7 7 52 18 20 14 9 9 83 20 26 18 12 12 104 28 33 21 15 14 125 34 48 23 17 16 146 45 54 25 19 18 157 55 60 26 20 20 15

Density [g/g]

375 385 380 390 380 375



Seite | 30

Tap Water (Hardness 4) at 20 °C


5 1 1 2 2 0 310 1 1 3 2 1 420 1 2 4 3 1 460 2 2 4 3 2 4

120 2 2 5 3 2 4480 2 3 5 5 4 4

Days 1 5 7 9 10 8 62 12 13 10 12 12 73 15 16 12 15 15 84 20 23 13 18 17 105 22 25 15 20 20 136 24 28 18 22 22 147 28 31 20 24 24 14

Density [g/g]

365 370 385 390 385 375



Seite | 31

Tap Water (Hardness 4) at 60 °C


5 0 0 1 1 1 210 1 1 2 1 1 220 1 1 2 2 1 360 1 1 3 2 1 3

120 2 2 4 3 2 4480 2 3 4 3 2 5

Days 1 7 10 10 12 10 92 15 18 14 14 13 113 18 24 16 17 17 134 25 30 18 21 21 155 30 37 22 24 23 166 35 45 27 29 25 177 40 50 30 32 27 17

Density [g/g]

380 395 375 380 390 370



Seite | 32

Synthetic Seawater (DIN 50900) at 20 °C


5 2 2 1 3 1 210 3 5 1 3 2 220 3 5 1 3 2 260 3 5 2 4 2 2

120 3 7 2 4 2 3480 3 7 2 4 3 3

Days 1 5 10 8 10 5 72 14 26 12 14 8 93 16 29 14 16 10 104 20 34 16 17 12 125 22 38 17 18 14 146 24 40 19 18 16 157 26 44 20 24 18 15

Density [g/g]

365 370 395 385 370 375



Seite | 33

Synthetic Seawater (DIN 50900) at 60 °C


5 0 1 0 1 1 210 1 1 0 1 1 220 1 1 1 2 1 260 2 2 1 2 2 3

120 2 2 2 2 3 3480 3 3 2 3 4 3

Days 1 7 9 6 10 6 82 16 18 15 16 10 113 20 25 19 18 12 134 25 31 22 20 15 145 27 36 25 23 18 176 30 42 27 25 19 187 32 48 29 30 21 18

Density [g/g]

395 390 370 375 365 380


Discussion and Conclusion

Seite | 34

Correlation E-Modulus and Penetrationlength (DI-Water at 20 °C]


Discussion and Conclusion

Seite | 35

Not the initial swell speed and high absorption capacity guaranted long term sealing.

Important is rheological structure and hydrolysis stability of swollen SAP is key factor.

Testing the parameters hydrolysis-stability and permeability of swollen SAP at higher temperatures show performance differences in short time.


Expression of Thanks

Seite | 36

Mr. Alton DeatonDr. Jochen Houben

Mr. Bobby MitraDr. Scott Smith

and

all of you for your interest.

Documents

Platzhalter Titelbild Superabsorbent Polymers (SAP) as Water-Blocking Components in Cables Martin Tennie ([email protected]) ICC Meeting November