preparation, structure and properties of the nano...
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Preparation, Structure and Properties Preparation, Structure and Properties of the Nano Reinforced; Thermal of the Nano Reinforced; Thermal Conductive Rubber Composites Conductive Rubber Composites
Lu, Lu, YonglaiYonglai; Zhang, ; Zhang, LiqunLiqun; ; FengFeng, , YaolingYaoling; Wang, ; Wang, ZhenhuaZhenhua; ; Ding, Ding, JingboJingbo
ContentsContents1. Introduction and Background2. Nano-ZnO filled systems3. Nano-Al2O3 filled systems4. Conclusions5. Acknowledgement
1. Introduction and Background1. Introduction and BackgroundAs well known to us,due to high elastic feature of rubber, many products working in dynamic condition must be made of rubber.
Tyre
Rubber Belts
In order to satisfy the practical applications, rubber reinforcement is very essential and necessary. Among all kinds of methods, compounding nano fillers is the most effective. Some traditional therories in rubber reinforcement have been developed on basis of much previous research work
1. Introduction and Background1. Introduction and Background
1 Strong bond and weak bond theory[1]
2 the model of the limited extensibility of rubber[2]
3 molecular chains slippage model [3]
4 Glass Shell Model [4]
[1] Naunton W J S. The applied science of rubber [M]. Edward Arnold Ltd.: London, 1961: 207-253.[2] Kraus, G. Reinforcement of Elastomers [M]. (Ed) Interscience Publishers: New York, 1965: 125-152.[3] Thor L. Smith, James A. Rinde. Ultimate tensile properties of elastomers. V. Rupture in constrained biaxial tensions [J]. Journal of Polymer Science Part A-2: Polymer Physics, 1969, 7(4): 675-685.[4] Boonstra B B. Mixing of carbon black and polymer: Interaction and reinforcement [J]. Journal of Applied Polymer Science, 1967, 11(3): 389-406.
Theories In Rubber
Reinforcment
Theories In Rubber
Reinforcment
“Nano-reinforcing is the predominant condition for the efficient reinforcement of rubber.” “Nano scale is necessary for efficient reinforcing rubber.” These viewpoints have been verified according to many researchers’ work and practical industry applications. For example: carbon black, with less than 100nm primary particle size, widely used in rubber industry.
1. Introduction and Background1. Introduction and Background
1. Introduction and Background1. Introduction and Background
Rubber-rubber frictionRubber-rubber friction
Filler-filler friction
FillerFiller--rubber frictionrubber friction
Microcosmic causes of heat
build-up
Main factors
Although fillers could endow the rubber product with good performances, but as well increase the heat build-up in dynamic serving conditions.
1. Introduction and Background1. Introduction and Background
Heat build-up
Heat build-up
Poor thermal conductivityPoor thermal conductivity
Heat accumulation leading to the internal high temperature
Heat accumulation leading to the internal high temperature
Deteriorating the utilized propertiesDeteriorating the
utilized properties
Accelerating the aging
Accelerating the aging
Rubber chains will be broken downStructural damage occurs in rubber products
Influencing the service life significantly, even safety problem
Harm of heat build-upHarm of heat build-up
1. Introduction and Background1. Introduction and Background
Schematic view of Bias tyre
Damage in tire shoulder
Much work has been done for improving the dynamic mechanical properties of composites: TWO strategies
Decreasing heat build-up
◆Decreasing the heat build-up,improving the dynamic mechanical properties
Conducting heat build-up
◆Increasing the thermal conductivity of rubber composites, conducting the heat build-up in time, and sovling the heat accumulation
Choosing novel rubber matrix such as SSBR; Increasing the filler-rubber interaction; Improving the filler dispersion, etc.Choosing novel rubber matrix such as SSBR; Increasing the filler-rubber interaction; Improving the filler dispersion, etc.
Filling the thermal conductive fillers, such as short stainlesssteel fiber, etc.Filling the thermal conductive fillers, such as short stainlesssteel fiber, etc.
Main FocusMain
Focus
Advantage:conducting the heat, solving the heat accumulationLimitation:thermal conductive fillers such as steel fiber perform
bad in reinforcing rubber matrix!
Advantage:conducting the heat, solving the heat accumulationLimitation:thermal conductive fillers such as steel fiber perform
bad in reinforcing rubber matrix!
Advantage:simple & effective, widely usedLimitation:Not solving the heat accumulation
from roots !
Advantage:simple & effective, widely usedLimitation:Not solving the heat accumulation
from roots !
1. Introduction and Background1. Introduction and Background
OurAims
• nano particles
Efficient reinforcement
Increasing thermal conductivity
• Thermal condutivefillers
Conducting the heat build-upDecreasing the heat accumulationImproving the dynamic propertiesExtending the service lifeDecreasing heat
build-up
• Inproving the dispersion and filler rubber interaction
Our StrategyOur Strategy
Enhancing the mechanical properties
Novel nano-reinforced thermal conductive rubber compositesNovel nano-reinforced thermal conductive rubber composites
Nano sized thermal conductive fillers, such as nano-ZnO and nano-Al2O3
Exploring the suitable modification method and treatment conditions
Rubber reinforced by nanoRubber reinforced by nano-- ZnOZnO or Alor Al22OO33
2. Nano2. Nano--ZnOZnO filled Systemfilled SystemDispersion morphologyPayne effectMechanism of in-situ modification with silane coupling agent Si69Static mechanical propertiesDynamic mechnical properties
Morphology Morphology observations of observations of nanonano--ZnOZnO particlesparticles
SEM micrographs of nano-ZnO particles
About 50nm
3.1 EPDM-nano ZnO
Dispersion state of nanoDispersion state of nano--ZnOZnO in EPDM in EPDM composites composites
Untreated ZnO filled
TEM images of nano-ZnO filled vulcanizatesLoading: 180phr Volume friction: 18%
TEM images of nano-ZnO filled vulcanizatesLoading: 180phr Volume friction: 18%
Si69 in-situ modified ZnO filled
Payne effectPayne effect
Payne effect of nano-ZnO filled gross rubber: (a) untreated nano-ZnOfilled composites; (b) in-situ modified nano-ZnO filled composites.
Decreased filler network, better dispersion state
Untreated ZnO filled Si69 in-situ modified ZnO filled
Stor
age
mod
ulus
G’/K
Pa
Stor
age
mod
ulus
G’/K
Pa
Strain/% Strain/%
Mechanism of InMechanism of In--situ Modification with Si69situ Modification with Si69——FTIRFTIR
4000 3500 3000 2500 2000 1500 1000
b
a
3448
1090
2926
Wavenumbers/cm-1
2977
Comparison of normalized FT-IR spectra among (a) Si69 pretreated nano-ZnO particles; (b) untreated nano-ZnO particles. (Normalized)
–CH2–& –CH3
–CH2–& –CH3
-OH-OH–Si–O––Si–O–
Mechanism of InMechanism of In--situ Modification with Si69situ Modification with Si69——SchematicSchematic
(a) Reaction between Zinc oxide particles (ZnO) and silicon coupling agent Si69
(b) Reaction between treated Zinc oxide particles (ZnO) and rubber chains
OH
OH
SiO
(CH2)3O-C2H5OH Sa
SiO (CH2)3 Sb
SiC2H5O
C2H5OC2H5O Si OC2H5
OC2H5
OC2H5
S4 (CH2)3(CH2)3
OC2H5
OC2H5C2H5O
ZnO
ZnO
ZnO
SRubber
SiO
(CH2)3O Sa
SiO (CH2)3 Sb
OC2H5
OC2H5C2H5O
SiO
(CH2)3O Sa
SiO (CH2)3 Sb
OC2H5
OC2H5C2H5O
ZnO
ZnO
ZnO
ZnO
Being dispersed and surface modified in the compounds meanwhile, under shear stress and high temperature
During curing, chemical bonds generate between nano particles and rubber chains
Schematic of the reactions during the in-situ modification procedure
0 50 100 150 200 2500
2
4
6
8
10
12
14
16
nano-ZnO nano-ZnO+Si69
Tens
ile s
tren
gth/
MPa
Loading of filler/phr0 50 100 150 200 250
0.5
1.0
1.5
2.0
2.5
3.0
3.5
Stre
ss a
t 100
% e
long
atio
nLoading of filler/phr
nano-ZnO nano-ZnO+Si69
Mechanical properties of nanoMechanical properties of nano--ZnOZnO/EPDM /EPDM compositescomposites
Tensile strength Stress at 100% Elongation
UntreatedUntreated
Si69 in-situ modifiedSi69 in-situ modified
SEM images of tensile section of nano-ZnO filled composites
Loading:180phr Volume fratcion:18%
SEM images of tensile section of nano-ZnO filled composites
Loading:180phr Volume fratcion:18%
0 50 100 150 200 250
0
10
20
30
40
50 nano-ZnO nano-ZnO+Si69
Perm
anen
t set
/%Loading of filler/phr
Mechanical properties of nanoMechanical properties of nano--ZnOZnO/EPDM /EPDM compositescomposites
Elongation at break Tensile permanent set
0 50 100 150 200 250200
300
400
500
600
nano-ZnO nano-ZnO+Si69
Elon
gatio
n at
bre
ak/%
Loading of filler/phr
Nano-ZnO performs well in reinforcing EPDM rubber, and in-situ modification with Si69 can improve the mechanical properties of nano-ZnOfilled composites effectively.
Instrument:FOX50-110 Thermal conductivity tester (Laser Comp, Inc. USA).Conditions:Temp. of cooling and heating calorimeter:20℃ and 40℃
Contact pressure:414KPaSample size:Disc shaped, Φ60mm×6mm
Thermal conductivity of NanoThermal conductivity of Nano--ZnOZnO/EPDM /EPDM CompositesComposites
Dynamic mechanical properties of NanoDynamic mechanical properties of Nano--ZnOZnO/EPDM Composites/EPDM Composites
1 10 1000.0
0.1
0.2
0.3
0.4
0.5
0.6
10 phr 20 phr 40 phr 60 phr 80 phr 110 phr 140 phr 180 phr 210 phr
tanδ
Strain/%
1 10 1000.0
0.1
0.2
0.3
0.4
0.5
0.6
tanδ
Strain/%
10 phr 20 phr 40 phr 60 phr 80 phr 110 phr 140 phr 180 phr 210 phr
Influence of in-situ modification on tanδ of nano-ZnO filled composites as a function of the filler loading
Si69 in-situ modified
In-situ modification with Si69 enhances the filler-rubber interaction effectively, leading to the decreased tanδ
Compression fatigue properties of NanoCompression fatigue properties of Nano--ZnOZnO/EPDM Composites/EPDM Composites
In-situ modification with Si69 improves the compression fatigue properties obviously, espectially at high lodings
0 50 100 150 200 2500
5
10
15
20
25
30
35
40
45
nano-ZnO nano-ZnO+Si69
H /℃
Loading of filler/phr0 50 100 150 200 250
0
2
4
6
8
10
12
14
16
18
20
nano-ZnO nano-ZnO+Si69
D/%
Loading of filler/phr
Influence of in-situ modification on compression fatigue properties of nano-ZnO filled composites
Compression heat build-up Difference D
D represents the difference between ultimate compression deformation rate and initial one
3.3. NanoNano--AlAl22OO33 filled Systemsfilled SystemsDispersion morphologyPayne effectStatic mechanical propertiesDynamic mechnical propertiesExtending to NR system
Morphology Morphology observations of nanoobservations of nano--AlAl22OO33 particlesparticles
SEM micrographs of nano-Al2O3 particles
Morphology of nano Al2O3
Dispersion state of nanoDispersion state of nano--AlAl22OO33 in EPDM in EPDM composites composites
Si69 in-situ modification
TEM images of nano-Al2O3 filled vulcanizatesLoading:149phr ; Volume fraction≈20%
TEM images of nano-Al2O3 filled vulcanizatesLoading:149phr ; Volume fraction≈20%Untreated
Payne effectPayne effect
1 10 1000.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0% 2.4% 4.6% 8.9% 11.8% 14.6% 18.1% 20.4%
G'/M
PaStrain/%
1 10 1000.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
G'/M
Pa
Strain/%
2.5% 4.8% 9.3% 12.4% 15.3% 18.8% 21.2%
At the same loading, storage modulus G’ of in-situ modified nano-Al2O3 filled composites is lower, which indicates that in-situ modification with Si69 decreases the filler-filler interaction and weakens the filler network effectively.
Influence of in-situ modification on Payne effect of nano-Al2O3 filled EPDM composites
Untreated Si69 in-situ modification
Stress at 100% elongation
0 5 10 15 20 250
2
4
6
8
10
12
14
n-Al2O3 n-Al2O3+Si69
Tens
le s
tren
gth/
MPa
Volume fraction/%0 5 10 15 20 25
0.5
1.0
1.5
2.0
2.5
3.0
3.5 n-Al2O3 n-Al2O3+Si69
Stre
ss a
t 100
% e
long
atio
n/M
PaVolume fraction/%
Untreated
Si69 in-situ modification
Mechanical properties of nanoMechanical properties of nano--AlAl22OO33filled EPDM compositesfilled EPDM composites
Tensile strength
0 5 10 15 20 25250
300
350
400
450
500
550 n-Al2O3 n-Al2O3+Si69
Elon
gatio
n at
bre
ak/%
Volume fraction/%0 5 10 15 20 25
0
5
10
15
20
25
30 n-Al2O3 n-Al2O3+Si69
Volume fraction/%
Perm
anen
t set
/%
Elongation at break Tensile permanent set
nano-Al2O3 also performs well in reinforcing EPDM rubber, and in-situ modification with Si69 can improve the mechanical properties of nano-Al2O3filled composites, as well as nano-ZnO filled systems.
Mechanical properties of nanoMechanical properties of nano--AlAl22OO33filled EPDM compositesfilled EPDM composites
Loading/phr
Volumefraction
/%
Nano-Al2O3/EPDMCompositesλ /[W·mK-1]
In-situ modified nano-Al2O3/EPDM Composites
λ /[W·mK-1]
0 0 0.178 0.17814 2.46 0.197 0.19328 4.81 0.216 0.21342 9.34 0.266 0.25077 12.4 0.304 0.292100 15.3 0.347 0.322128 18.8 0.404 0.374
149 20.4 0.406 0.408
Thermal conductivity of NanoThermal conductivity of Nano--AlAl22OO33/EPDM /EPDM CompositesComposites
Increasing
Increasing
Conditions:Temp. of cooling and heating calorimeter:20℃ and 40℃Contact pressure:414KPa
Sample size:Disc shaped, Φ60mm×6mm
1 10 1000.0
0.1
0.2
0.3
0.4
0% 2.4% 4.6% 8.9% 11.8% 14.6% 18.1% 20.4%ta
nδStrain/%
1 10 1000.0
0.1
0.2
0.3
0.4
2.5% 4.8% 9.3% 12.4% 15.3% 18.8% 21.2%
tanδ
Strain/%
Influence of inInfluence of in--situ modification on situ modification on tantanδδ of nanoof nano--AlAl22OO33filled composites as a function of the filler volume fractionfilled composites as a function of the filler volume fraction
Dynamic mechanical properties of Nano-Al2O3/EPDM Composites
Untreated Si69 in-situ modification
0 5 10 15 20 25
5
10
15
20
25
H /℃
Volume fraction/%
nano-Al2O3
nano-Al2O3+Si69
0 5 10 15 20 25
0
1
2
3 nano-Al2O3
nano-Al2O3+Si69
D/%
Volume fraction/%
Influence of in-situ modification on compression fatigue properties of nano-Al2O3 filled composites with respect to the filler volume fraction
At the same volume fraction, after in-situ modification with Si69 heat build-up decreases and the difference D is improved obviously
Compression fatigue properties of Nano-Al2O3/EPDM Composites
Compression heat build-up Difference D
Extending to NR systemExtending to NR system
(b)
(a)
Mechnical Properties of nano-Al2O3 filled NR composites as function of the filler loading
(b)
(c)
NR filled with 210phr Al2O3 hasThermal conductivity 0.5W/(m.K)Compression heat build-up 16oCDynamic compression permanent set <2%.
Comparison of mechanical (static and dynamic) and thermal conductive properties of composites compounded with in-situ modified nano-ZnO, nano-Al2O3 and traditional reinforcing fillers
3. Comparisons to traditional reinforcing 3. Comparisons to traditional reinforcing fillers filled systemsfillers filled systems
18.3
Loading/phr
Volume fraction/%
Tensile strength/MPa
Elongation at break/%
Permanent set/%
Heat build-up/℃
Difference D/%
λ /[W·m-1·K-1] ℃
Compared to the traditional reinforcing fillers such as carbon black N330 and silica, nano-ZnO and nano-Al2O3 particles assisted by in-situ modification with Si69 increase the thermal conductivity greatly and perform well in reinforcing the EPDM matrix, especially excellent dynamic mechanical properties such as lower compression heat build-up and better fatigue resistance.
4. Conclusions4. Conclusions(1) Nano-ZnO and nano-Al2O3 can enhance the thermal conductivity greatly, and meanwhile perform well in the reinforcing EPDM rubber. However, its dynamic mechanical properties are not good enough. (2) In-situ modification with Si69 can improve the mechanical properties of nano-ZnO and nano-Al2O3 filled composites without influencing the thermal conductivity obviously. Similar results could be obtained in nano-Al2O3 filled NR systems.(3) Compared to the traditional reinforcing fillers such as carbon black N330 and silica, nano-ZnO and nano-Al2O3 particles assisted by in-situ modification with Si69 increase the thermal conductivity greatly and perform well in reinforcing the EPDM matrix, especially excellent dynamic mechanical properties such as lower compression heat build-up and better fatigue resistance.