Applications Elastomers - VKRT · Applications Elastomers VKRT Bijeenkomst 8 Februari 2007. Hay Berden Author: J. Schawe Date: June 06 Vers.1 Approved: Ni Jing

Applications Elastomers

VKRT Bijeenkomst8 Februari 2007.

Hay Berden

Author: J. SchaweDate: June 06 Vers.1Approved: Ni Jing

1 Internal usage only

Agenda

1. Do you need to know the influence the glasstransition temperature has on your product?

2. Is your product used in an area that requiresit to be thermal stable?

3. You are interested in measuring the productformulation in % or phr?

4. Does part of your process optimizationinvolve vulcanization development?

5. Do you need to understand the influencedifferent fillers have on your material?


Agenda

6. Would you like to know whether yourmaterials swell in contact with solvents ormoisture?

7. Are you interested in process simulations toimprove product output?

8. Is the cross-linking density of your productimportant for the final application?

9. Do you need to understand the effect of highand low frequency vibrations on yourproduct?


Introduction

Typical questions regarding elastomers


1 Glass transition

Do you need to know the influence the glass transition temperaturehas on your product?

The glass transition- determines the working range

of a material- determines the mechanical behavior- allows analysis of the decomposition

TA Handbook, Collected Applications: ElastomersChapter 4.1.2, 4.5.3, 4.5.5, 3.4.3


1 Glass transition

Rubbers show different glass transition temperatures

NR EPDM

L-SBRNBR

CR

E-SBR

silicone rubber

Wg^-10.2

°C-120 -100 -80 -60 -40 -20 0

êxo Glass Trans ition of Different Rubbers 07.07.2002 13:03:33

Schawe: JSchawe SystemeRTAMETTLER TOLEDO S

0.45−20L-SBR

0.50−32NBR

0.54−50E-SBR

0.33−37CR

0.43−53EPDM

0.46−62NR

0.32−123Silicone rubber

∆cpIn J/gK

TgIn °C

Polymer


1 Glass transition

Analysis of polymer blends by DSC

NBR/CR blend:

24.4% NBR

24.4% CR

33.7% Fillers

NR/SBR blend:

25.5% NR

7.2% SBR

53.3% Fillers

Glass transition temperatureà identificationGlass transition intensity à content determination

Glass TransitionMidpoint ASTM,IEC -44.10 °CDelta cp ASTM,IEC 38.906e-03 Jg^-1K^-1

Glass TransitionMidpoint ASTM,IEC -58.85 °CDelta cp ASTM,IEC 0.155 Jg^-1K̂ -1



NR/SBR

NBR/CR

Wg^-10.1

°C-120 -100 -80 -60 -40 -20 0

êxo DSC of Incompatibl e Polymer Blends 07.07.2002 15:43:53



1 Glass transition

Glass transition measurement by DMA

DMA characterizes the glass transition and mechanical properties

1000 Hz100 Hz

10 Hz1 Hz

δtan

0

1

2

°C-40 -20 0 20 40 60 80

G"

G' 1 Hz

1000 Hz100 Hz

10 HzPa

10^8

10^7

10^6

10^5

°C-40 -20 0 20 40 60 80

Temperature Scan of Unvulcanized SBR 08.07.2002 10:01:55

Lab: JSchawe SW 7.00 B10+eRTAMETTLER TOLEDO S


1 Glass transition

Glass transition measurement of blends by DMA

40% NR

60% L-SBR

G"

G'

100 Hz10 Hz1 Hz

Pa10^9

10^8

10^7

10^6

10^5

10^4

°C-80 -60 -40 -20 0 20 40 60 80

Shear Modulus of an SBR/NR Blend 15.07.2002 11:29:54



2 Thermal stability

Is your product used in an area that requires it to be thermal stable?

TGA shows differences inthermal stability

TA Handbook, Collected Applications: ElastomersChapter 4.1.1,


2 Thermal stability

Comparison of different SBR materials

Emulsionpolymerized SBRcontains morevolatilecomponents thanSBR polymerizedin solution.

TGA delivers information of thermal stability

1

2

3

4

TGA VSL5025-0

Krylene 1500

%

0

50

°C100 200 300 400 500 600 700

DTG

%min^-150

°C100 200 300 400 500 600 700

TGA of SBR 07.07.2002 12:40:55



3 Compositional analysis

You are interested in measuring the product formulationin % or phr?

Compositional analysis,to determine the differentcomponents and therelated content of aformulation:

- Competition analysis- Quality control

TA Handbook, Collected Applications: ElastomersChapter 3.2.1, 4.5.1, 4.5.4



Different standards: ASTM E 1131, ASTM D 6370, ISO 9924,

NFT 46-047, UNI 8698, VDA 675135, etc.

Example 1: ASTM E 11311. RT to 600 °C at 10 K/min (50 ml/min nitrogen)2. 600 °C to 750 °C at 10 K/min (50 ml/min oxygen)

Example 2: ASTM D 63701. 50°C for 2 min (75 ml/min nitrogen)2. 50°C to 560 °C at 10 K/min (75 ml/min nitrogen)3. 560 °C to 300 °C at -30 K/min (75 ml/min nitrogen)4. 300°C for 2 min (75 ml/min nitrogen)5. 300°C to 800 °C at 10 K/min (75 ml/min oxygen)



Simple compositional analysis

Analysis results:

volatiles: 3.06%polymer: 62.89%carbon black: 31.52%ash: 2.29%

volatiles: 4.8 phrpolymer: 100.0 phrcarbon black: 50.1 phrash: 3.6 phr

3rd step2nd step1st step

TGA

Step -31.5186 % -4.1620 mgResidue 2.2912 % 0.3025 mg

Step -62.8888 % -8.3045 mg

Step -3.0646 % -0.4047 mg

%50

DTG

%°C^-10.5

°C200 400 600

TGA Analysis of Elas tomers 06.07.2002 19:12:16


phr (part per hundred rubber)Example: CB in phr = 31.52*100/62.89



If carbon black a pyrolysis product:

Analysis results:

The carbon blackcontent is 43%.

10% is pyrolysis product.

TGA

Step -52.5130 % -9.8099 mgStep -42.9756 %

-6.0136 mg

Step -10.4131 % -1.4571 mg

%

0

20

40

60

80

100

°C200 400 600 800

DTG

10 K/min 30 K/min

%°C^-11

TGA of CR with Different Methods 07.07.2002 14:55:55




Polymers with different decomposition temperature

432

1TGA

E

D

CB

A

%100

DTG

EDC

B

A%min^-110

°C200 400 600 800

TGA of NR Blends 07.07.2002 15:26:25


Analysis results:

Two peaks in thedecomposition step



SBR,EPDM,

EPDM,pEPDM

pp

p

ccc

∆+∆

∆⋅=

αα

Polymers with similar decomposition temperatures (12.6%SBR/25.5% EPDM)

Overlap ofthe glass transition of SBRand the EPDM melting process

SBR

EPDMIntegral -48.75 mJ normalized -1.72 Jg^-1Baseline Type tang. right

Glass TransitionMidpoint ASTM,IEC -40.41 °CDelta cp ASTM,IEC 57.898e-03 Jg^-1K^-1

Glass TransitionMidpoint ASTM,IEC -57.14 °CDelta cp ASTM,IEC 0.135 Jg^-1K^-1

Glass Transition

Glass transitionof EPDM

Integral -48.75 mJ

mW5

°C-120 -100 -80 -60 -40 -20 0 20

êxo DSC of a EPDM/SBR Blend 13.07.2002 13:42:51


TGA delivers the polymer content;DSC separates the polymer components

This calculation gives a value of 27.3% for EPDM, andconsequently 11.7% for SBR.

TGA

Polymer2 K/minStep -39.0583 % -4.1448 mg

Step -14.1539 % -1.5020 mg

%

60

80

°C100 200 300 400

DTG

%°C^-10.5

TGA of an EPDM/SBR Bl end 13.07.2002 13:40:04



4 Vulcanization kinetics

Does part of your process optimization involve vulcanizationdevelopment?

Most technical reason forelastomer failure isinsufficient vulcanization.

Vulcanization is energyand time consuming.

TA Handbook, Collected Applications: ElastomersChapter 3.1.3



Vulcanization of different elastomersEnthapy of reaction

depends on filler

crosslinker etc.

Integral 126.00 mJ normalized 4.59 Jg^-1Peak 153.64 °C

Integral 528.54 mJ normalized 11.29 Jg^-1Peak 179.74 °C

Silicone elastomer

NBRWg^-1

0.2

°C-50 0 50 100 150 200 250

êxo Vulcanization Reaction 19.06.2002 16:04:15




Kinetic evaluation of vulcanization reaction (DSC measurements)

20 K/min

15 K/min

10 K/min

5 K/min

2 K/min

1 K/min

Wg^-10.1

°C100 150 200

êxo Vulcanization Reaction of NBR 06.07.2002 18:47:46




Kinetic evaluation of vulcanization reaction (MFK evaluation)

MFK evaluation helps for process optimization.

1 K/min 5 K/min

2 K/min%

0

20

40

60

80

°C100 150

Activation energy

kJmol^-1

100

120

140

%50140 °C130 °C120 °C110 °C

100 °C

%

0

20

40

60

80

min0 20 40

êxo Model Free Kinetics of Vul canization 06.08.2002 10:32:34



5 Filler influence

Do you need to understand the influence different fillers have onyour material?

The interaction between filler andpolymer matrix improves themechanical behavior of elastomers.

TGA for identificationTMA and DMA for determinationof mechanical properties

TA Handbook, Collected Applications: ElastomersChapter 4.3.3, 4.3.4, 4.3.5, 4.5.5


5 Filler influence

Determination of the filler content:

W313

W309

W305 Carbon black

PolymerVolatiles

%

0

50

100

min

°C100 200 300 400 500 600600 700

10 20 30 40 50 60

TGA of EPDM wi th Carbon Black 07.07.2002 14:42:47


Analysis results:

carbon black u

combustion step

inorganic filler u

residue


5 Filler influence

Comparison between different carbon blacks:

Step -44.3938 %Midpoint 602.18 °C

Step -44.1928 %Midpoint 577.78 °C

Step -44.5310 %Midpoint 563.77 °C

Step -43.9601 %Midpoint 554.42 °C

w311

W312

w313

w314

Midpoint 563.77 °C%

0

20

40

60

80

°C100 200 300 400 500 600 700

TGA of EPDM wi th Di fferent Carbon Blacks 13.07.2002 12:52:45


Analysis results:

higher reactivity u

lower midpointtemperature of thecombustion step


5 Filler influence

20 25 30 35 40 450

5

10

15

20

25

Youn

g's

mod

ulus

in M

Pa

Carbon black content in %

Filler type N990 N550

Young’s modulus in the rubbery plateau by TMA:

Isotherm 26’C. kracht tussen 0.05 en 1 N variabel. Analysis result:

The filler influence of the modulus in the rubbery plateau can bemeasured be DLTMA

44.3% N55034.7% N55021.0% N550

Force : 50 mN / 1 N

%

96

97

98

99

min2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4

DLTMA of EPDM with Different Fil lers 13.07.2002 12:54:56



6 Expansion coefficient

Is your product affected by expansion or contraction when thetemperature changes?

Measurement of the

Thermal expansion coefficient by TMA



6 Expansion coefficient

The thermal expansion by TMA:

The expansion coefficient depends on polymer and filler

silicone elastomerwith

61.6% inorganicfiller (sample A)

56.0% inorganicfiller (sample B)

Load 0.02 N.

5mm thick

Sample B

Sample A

%

100

102

104

106

°C100 200

Expansion Coefficient °C ppm°C^-1 50.00 257.73100.00 247.70150.00 258.77200.00 253.45250.00 251.06300.00 238.01

Expansion Coefficient °C ppm°C^-1 50.00 208.42100.00 202.19150.00 203.67200.00 203.96250.00 201.02300.00 176.57

ppm°C^-1

150

200

°C100 200

Expansion Coeffi cient 19.06.2002 16:58:23



7 Swelling in solvent

Would you like to know whether your materials swell in contact withsolvents or moisture?

Swelling is important forapplication in

- automotive industry- petrochemical industry- medicine technology- sealing techniques- recycling etc.



7 Swelling in solvent

isothermal 25’C Force 0.1N

Swelling of different elastomers in toluene

NBR

FPM

MQ

EPDM

%

100

110

120

130

min0 10 20 30

Swel ling Measurements by TMA 07.07.2002 16:54:56


MQ: methyl-siliconerubber

EPDM: ethylene-propylene-dieneterpolymer

NBR: acrylonitrile-butadiene rubber

FPM: fluororubber


8 Improve product output

Are you interested in process simulations to improve productoutput?

The product output is mainly determined by:- degree of vulcanization- vulcanization temperature and time- the used filler and filler content

For simulation physical properties also important:- heat capacity, glass transition temperature- thermal expansion coefficient- mechanical modules- cross-linking density- reaction kinetics

These topics are described in point 1, 4, 5, 6, 7, 9, 10


9 Cross-linking density

Is the cross-linking density of your product important for the finalapplication?

The cross-linking densityInfluences the mechanical behavior:

- modulus- hardness- flow behavior- mechanical long term stability- swelling behavior- damping behavior

TA Handbook, Collected Applications: ElastomersChapter 4.8.1, 4.2.2



Creep measurement of o-rings by TMA:

The creep recovery behavior depends on the cross-linkingdensity

Increasing cross-linking densitydecreases viscousflow and increasesthe modulus.

Increasing fillercontent increases themodulus but has onlya small influence onthe flow behavior.EPDM

FPM

0.01 N1 N0.01 N

%5

min0 20 40 60 80

Creep Measurements with TMA 07.07.2002 16:51:17




Influence of the degree of cross-linking on the mechanical behavior

TRG

2=κ

Influence ofvulcanization on themechanical properties

SBR1: 0.5 phr sulfur

SBR2: 2 phr sulfur

SBR3: 4 phr sulfur

SBR4: 8 phr sulfur

Cross-linking density, κ,can be estimated from theplateau modulus G:

DMA determines the mechanical properties at different degreeof vulcanization

SBR4

SBR3

SBR2

SBR1

G''

G'Pa

10^8

10^7

10^6

10^5

10^4

°C-40 -20 0 20 40 60 80

SBR wi th Different Network Densities 15.07.2002 11:19:11



10 Vibration damping

Do you need to understand the effect of high and low frequencyvibrations on your product?

The knowledge of the vibration

behavior is important for the

vibration and sound damping.




Temperature scan at different frequencies:

Analysis result:NBR 24.4%

CR 24.4%

Filler 33.7%

This material shows a large loss factor around room temperature

1000 Hz100 Hz10 Hz1 Hz

G"

G'MPa

10^2

10^1

10^0

°C-80 -60 -40 -20 0 20 40

δtan

0.0

0.2

0.4

°C-80 -60 -40 -20 0 20 40

Temperature Scan of an NBR/CR Elastomer 15.07.2002 11:42:15




Expansion of the frequency range by master curve:

Analysis result:

Master curves allows the determination of the mechanicalbehavior in a very wide frequency range

reference temperature: 30.5 °C

G''

G'MPa

10̂ 3

10̂ 2

10̂ 1

10̂ 0

10^-1Hz10̂ 1510̂ 1410^1310^1210̂ 1110̂ 1010^910̂ 810̂ 710̂ 610̂ 510^410̂ 310̂ 210̂ 110^010̂ -110̂ -210̂ -310^-410̂ -5

Mastercurve 07.06.2006 17:59:25

STARe SW 9.01Lab: METTLER


Conclusion

!MCharacterization of additivesMReaction enthalpy

!MMelting and crystallization!!!Vulcanization system!!MVulcanization

MSwelling in solventMExpansion, contraction

!MSoftening temperatureM!Evaporation/ desorption/ vaporization

M!Carbon black activityMFiller activity

M!Filler content/ carbon black contentMDamping behaviorM!Elasticity modulusM!Viscoelastic behavior

!MOxidative stabilityM!Thermal stability/ decomposition

!M!CompositionM!MGlass transition

DMATMATGADSC

Applications Elastomers - VKRT · Applications Elastomers VKRT Bijeenkomst 8 Februari 2007. Hay Berden Author: J. Schawe Date: June 06 Vers.1 Approved: Ni Jing

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