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?
2 Internal usage only
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?
4 Internal usage only
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
5 Internal usage only
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
^exo 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
6 Internal usage only
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
Glass TransitionMidpoint ASTM,IEC -13.60 °CDelta cp ASTM,IEC 0.110 Jg^-1K̂ -1
Glass TransitionMidpoint ASTM,IEC -49.68 °CDelta cp ASTM,IEC 0.105 Jg^-1K̂ -1
NR/SBR
NBR/CR
Wg^-10.1
°C-120 -100 -80 -60 -40 -20 0
^exo DSC of Incompatibl e Polymer Blends 07.07.2002 15:43:53
Schawe: JSchawe SystemeRTAMETTLER TOLEDO S
7 Internal usage only
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
8 Internal usage only
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
Lab: JSchawe SW 7.00 B10+eRTAMETTLER TOLEDO S
9 Internal usage only
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,
10 Internal usage only
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
Schawe: JSchawe SystemeRTAMETTLER TOLEDO S
11 Internal usage only
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
12 Internal usage only
3 Compositional analysis
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)
13 Internal usage only
3 Compositional analysis
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
Schawe: JSchawe SystemeRTAMETTLER TOLEDO S
phr (part per hundred rubber)Example: CB in phr = 31.52*100/62.89
14 Internal usage only
3 Compositional analysis
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
Schawe: JSchawe SystemeRTAMETTLER TOLEDO S
15 Internal usage only
3 Compositional analysis
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
Schawe: JSchawe SystemeRTAMETTLER TOLEDO S
Analysis results:
Two peaks in thedecomposition step
16 Internal usage only
3 Compositional analysis
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
^exo DSC of a EPDM/SBR Blend 13.07.2002 13:42:51
Schawe: JSchawe SystemeRTAMETTLER TOLEDO S
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
Schawe: JSchawe SystemeRTAMETTLER TOLEDO S
17 Internal usage only
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
18 Internal usage only
4 Vulcanization kinetics
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
^exo Vulcanization Reaction 19.06.2002 16:04:15
Schawe: JSchawe SystemeRTAMETTLER TOLEDO S
19 Internal usage only
4 Vulcanization kinetics
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
^exo Vulcanization Reaction of NBR 06.07.2002 18:47:46
Schawe: JSchawe SystemeRTAMETTLER TOLEDO S
20 Internal usage only
4 Vulcanization kinetics
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
^exo Model Free Kinetics of Vul canization 06.08.2002 10:32:34
Schawe: JSchawe SystemeRTAMETTLER TOLEDO S
21 Internal usage only
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
22 Internal usage only
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
Schawe: JSchawe SystemeRTAMETTLER TOLEDO S
Analysis results:
carbon black u
combustion step
inorganic filler u
residue
23 Internal usage only
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
Schawe: JSchawe SystemeRTAMETTLER TOLEDO S
Analysis results:
higher reactivity u
lower midpointtemperature of thecombustion step
24 Internal usage only
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
Schawe: JSchawe SystemeRTAMETTLER TOLEDO S
25 Internal usage only
6 Expansion coefficient
Is your product affected by expansion or contraction when thetemperature changes?
Measurement of the
Thermal expansion coefficient by TMA
TA Handbook, Collected Applications: ElastomersChapter 3.3.1
26 Internal usage only
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
Schawe: JSchawe SystemeRTAMETTLER TOLEDO S
27 Internal usage only
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.
TA Handbook, Collected Applications: ElastomersChapter 4.8.1
28 Internal usage only
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
Schawe: JSchawe SystemeRTAMETTLER TOLEDO S
MQ: methyl-siliconerubber
EPDM: ethylene-propylene-dieneterpolymer
NBR: acrylonitrile-butadiene rubber
FPM: fluororubber
29 Internal usage only
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
30 Internal usage only
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
31 Internal usage only
9 Cross-linking density
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
Schawe: JSchawe SystemeRTAMETTLER TOLEDO S
32 Internal usage only
9 Cross-linking density
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
Lab: JSchawe SW 7.00 B10+eRTAMETTLER TOLEDO S
33 Internal usage only
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.
TA Handbook, Collected Applications: ElastomersChapter 4.5.5
34 Internal usage only
10 Vibration 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
Lab: JSchawe SW 7.00 B10+eRTAMETTLER TOLEDO S
35 Internal usage only
10 Vibration damping
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
36 Internal usage only
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