special features of polymer modified binders

Petersen Conference 2004/JPP/07-04 1

JeanJean--Pascal Planche Pascal Planche –– Total FranceTotal FrancePetersen Asphalt Research Conference 2004Petersen Asphalt Research Conference 2004

Symposium on AdditivesSymposium on Additives

After PIARC C8 Rome 1998, Total published results, and After PIARC C8 Rome 1998, Total published results, and others…others…

Special Features Special Features of Polymer Modified Bindersof Polymer Modified Binders

2Petersen Conference 2004/JPP/07-04

Contents

•• Main polymer used in Bitumen modificationMain polymer used in Bitumen modification•• General mechanism of bitumen modificationGeneral mechanism of bitumen modification•• Special features of PmB’sSpecial features of PmB’s

-- Polymer nature and structure influencePolymer nature and structure influence•• Plastomer modified bindersPlastomer modified binders•• Elastomer modified bindersElastomer modified binders

-- Relationships microstructure Relationships microstructure –– propertiesproperties•• Base asphalt influenceBase asphalt influence•• Effect on ageing stabilityEffect on ageing stability•• Effect on storage stabilityEffect on storage stability

•• ConclusionsConclusions


= Styrene= Styrene = Butadiene= Butadiene

ELASTOMERS FOR BITUMEN MODIFICATION

STRUCTURES OF ELASTOMERSSTRUCTURES OF ELASTOMERS

Linear polymer (BR)Linear polymer (BR)

Branched polymer (BR)Branched polymer (BR)

Partially block Copolymer (SB)Partially block Copolymer (SB)

Block Copolymer (SBS)Block Copolymer (SBS)

Random Copolymer (SBR)Random Copolymer (SBR)


Polystyrene blocksPolystyrene blocks Polystyrene DomainsPolystyrene Domains Polybutadiene ChainsPolybutadiene Chains

ELASTOMERS FOR BITUMEN MODIFICATIONSTRUCTURE of THERMOPLASTIC ELASTOMERSSTRUCTURE of THERMOPLASTIC ELASTOMERS


Various styrene Various styrene contentscontentsMw = 180000Mw = 180000

00 200200 400400 600600 80080000

1010

2020

3030

Elongation (%)Elongation (%)

Str

ess

(S

tres

s ( M

Pa

MP

a ))

7575

1515

303039395555

6363

ELASTOMERS FOR BITUMEN MODIFICATIONINFLUENCE of the STYRENE CONTENT on SBS INFLUENCE of the STYRENE CONTENT on SBS ELASTOMER PROPERTIESELASTOMER PROPERTIES

Diani Diani et al Eurobitume 1989et al Eurobitume 1989


ELASTOMERS FOR BITUMEN MODIFICATION

INFLUENCE of MACROSTRUCTURE on SBS VISCOUS INFLUENCE of MACROSTRUCTURE on SBS VISCOUS BEHAVIOURBEHAVIOUR T = 140 °CT = 140 °C

1E+01E+0 1E+11E+1 1E+21E+2 1E+31E+31E+21E+2

3E+23E+2

1E+31E+3

3E+33E+3

1E+41E+4

3E+43E+4

1E+51E+5

3E+53E+5

Shear rate (1/s)Shear rate (1/s)

Ap

par

ent

Vis

cosi

ty (

Pa

s)A

pp

aren

t V

isco

sity

(P

a s) LinearLinear StarStar

SBS :SBS :Mw = 120000, Mw = 120000, styrene content = 30%styrene content = 30%

Diani Diani et al Eurobitume 1989et al Eurobitume 1989


PLASTOMERS FOR BITUMEN MODIFICATIONEthylene CopolymersEthylene CopolymersChemical CompositionChemical Composition

EVAEVA EMAEMA EBAEBA


PLASTOMERS FOR BITUMENMODIFICATIONEthylene Copolymers StructureEthylene Copolymers Structure

-> Viscoelastic behavior


OTHER PLASTOMER MODIFICATIONFunctional TER or COFunctional TER or CO--POLYMERSPOLYMERS

Developing Technology in the USADeveloping Technology in the USA

àà ““CrosslinkedCrosslinked”” Plastomer modified bindersPlastomer modified binders

EEthylenethylene(+ butyl Acrylate)(+ butyl Acrylate)+ glycidyle methacrylate+ glycidyle methacrylate

+ PPA activation ?+ PPA activation ?


POLYMERS FOR BITUMEN MODIFICATION Summary

•• Thermoplastic elastomer featuresThermoplastic elastomer features-- Soft (PB) and hard blocks (PS), incompatibleSoft (PB) and hard blocks (PS), incompatible

-- Physical properties, block length dependentPhysical properties, block length dependent

•• Elastomers for bitumen modification: mainly SB(S)Elastomers for bitumen modification: mainly SB(S)-- Block copolymers with radial or linear structuresBlock copolymers with radial or linear structures

-- Styrene content between 15 and 30% Styrene content between 15 and 30%

-- Mw between 80000 and 300000 DaltonsMw between 80000 and 300000 Daltons

•• Plastomer featuresPlastomer features-- Soft (coSoft (co--monomer effect) and hard crystalline segments (PE)monomer effect) and hard crystalline segments (PE)

-- Physical properties, Cristallinity and Mw (MI) dependentPhysical properties, Cristallinity and Mw (MI) dependent

•• Plastomers for bitumen modification: mainly EVAPlastomers for bitumen modification: mainly EVA-- Melt flow index 5 to 150Melt flow index 5 to 150

-- VA content between 15 and 35% (by weight)VA content between 15 and 35% (by weight)

-- Functional ethylene copolymers coming into playFunctional ethylene copolymers coming into play


LAYING & LAYING & HANDLINGHANDLING

SERVICESERVICE

Con

sist

ency

Con

sist

ency

TemperatureTemperature

Polymer Modified BitumenPolymer Modified Bitumen

Neat BitumenNeat Bitumen

Ideal BehaviourIdeal Behaviour

POLYMER MODIFIED BINDERS WHY MODIFY?

BEHAVIOUR CLASSICAL MODELLINGBEHAVIOUR CLASSICAL MODELLING


POLYMER MODIFIED BINDERS

EMPIRICALEMPIRICAL PROPERTIESPROPERTIESto observe to observe polymer effectpolymer effect on bitumen on bitumen modificationmodification


PLASTOMER MODIFIED BINDERS

EVA modified BITUMENSEVA modified BITUMENS ::Consistency: Penetration @ 25°C & R&B softening Consistency: Penetration @ 25°C & R&B softening pointpoint

R&B

Pen


PLASTOMER MODIFIED BINDERSEMA modified BITUMENSEMA modified BITUMENSInfluence of Melt Index (Mw) on R&B softening pointInfluence of Melt Index (Mw) on R&B softening point

3% EMA – R&B 10% EMA – R&B

MI effectMI effect


020406080

100120140160180

0 5 10 15 20

% Polymer

Pen

etra

tion

(0.1

mm

)

110 linear165 linear200 linear230 star

Mw x 1000

ELASTOMER MODIFIED BINDER

PenetrationPenetration


Mw x 1000

ELASTOMER MODIFIED BINDERELASTOMER MODIFIED BINDER

Ring & Ball Softening PointRing & Ball Softening Point

0

20

40

60

80

100

120

140

0 10 20

% Polymer

R&

B (°

C) 110 linear

165 linear200 linear230 star


0

1000

2000

3000

4000

5000

0 10 20

% Polymer

Vis

cosi

ty (m

Pa.

s)

110 linear165 linear200 linear230 star

Mw x 1000

ELASTOMER MODIFIED BINDER ELASTOMER MODIFIED BINDER

Dynamic Viscosity @ 180CDynamic Viscosity @ 180C


γ γ ω( ) cos( )t t= 0

σ σ ω δ( ) cos( )t t= +0

γ σ0 0,

tδ

POLYMER MODIFIED BINDERS

•• RHEOLOGICAL PROPERTIES RHEOLOGICAL PROPERTIES to observe to observe polymer polymer effecteffect on bitumen modificationon bitumen modification


Plain bitumensPlain bitumens

Unaged bitumens

0

30

60

90

1E+01 1E+03 1E+05 1E+07 1E+09

G* (Pa)

Bc (conventional)

Bo (oxydable)

T(°C) increase

Viscous

Elastic


Effect of polymer addition (SBS)Effect of polymer addition (SBS)before ageing

0

30

60

90

1E+01 1E+03 1E+05 1E+07 1E+09

G* (Pa)

Bc

Bc-SBS* (3%)

• ReinforcementReinforcement ofof thethe binder binder impartedimparted byby thethe polymerpolymer(hard / soft relaxation)(hard / soft relaxation)

BcBc--SBS* (6%)SBS* (6%)

•• TheThe relaxation relaxation is shifted towards higher temperatureis shifted towards higher temperatureas as polymerpolymer content content increasesincreases


4% SBS*3 Blend

Neat bitumenNeat bitumen

1E+00

1E+03

1E+06

1E+09

-150 -75 0 75 150

Temperature (°C)

G' (

Pa)

1E+00

1E+03

1E+06

1E+09

-150 -75 0 75 150

Temperature (°C)

G''

(Pa)


•• RHEOLOGICAL PROPERTIESRHEOLOGICAL PROPERTIES


Crosslinked ELASTOMER MODIFIEDBINDER

3%

A45

5%

3%

A65

3%

A85

-22

-20

-18

-16

-14

-12

-1060 65 70 75 80

T iso G*/sin d (C)

T is

o B

BR

(C)

A45A65A85

•• Influence of the Bitumen Grade & Polymer Content on Influence of the Bitumen Grade & Polymer Content on SHRP CriteriaSHRP Criteria



•• EVA modified bitumens : Temperature @ G*/sin EVA modified bitumens : Temperature @ G*/sin δδ =1 =1 KPaKPa

BrûléBrûlé et al, PIARC 1998 et al, PIARC 1998 RomeRome


-- due to EVA cristallinitydue to EVA cristallinity

-- No ageing effect; but effect on mix properties?No ageing effect; but effect on mix properties?

PLASTOMER MODIFIED BINDERSPLASTOMER MODIFIED BINDERSThermal History dependencyThermal History dependency

0

1 0

2 0

3 0

4 0

5 0

6 0

7 0

8 0

9 0

1,00E+00 1,00E+01 1,00E+02 1,00E+03 1,00E+04 1,00E+05 1,00E+06 1,00E+07 1,00E+08 1,00E+09

Complex Modulus (Pa)

Pha

se A

ngle

(°)

Temperature going down during testing in the rheometer

Temperature rising up during testing in the rheometer

0

1 0

2 0

3 0

4 0

5 0

6 0

7 0

8 0

9 0

1,00E+00 1,00E+01 1,00E+02 1,00E+03 1,00E+04 1,00E+05 1,00E+06 1,00E+07 1,00E+08 1,00E+09

Complex Modulus (Pa)

Pha

se A

ngle

(°)

Temperature going down during testing in the rheometer

Temperature rising up during testing in the rheometer

Complex Modulus

δδMeasures upon cooling

Measures upon heating

Mouillet et al E&E Congress 2004Mouillet et al E&E Congress 2004


PLASTOMER MODIFIED BINDERSInfluence of Thermal History on Cristallinity Influence of Thermal History on Cristallinity -- MeltingMelting

Largeaud Largeaud et alet al



•• Influence of thermal history on cristallinity Influence of thermal history on cristallinity -- CrystallizationCrystallization

Largeaud Largeaud et alet al


Repeated Creep Recovery for Plastomer modified Bitumens

0

0,0005

0,001

0,0015

0,002

0,0025

0,003

0,0035

0 2 4 6 8 10 12

Time (s)

Com

plia

nce

(Pa-1

)

76°C

70°C

64°C

Last cycle

Last cycle

Last cycle

First cycle

First cycle

First cycle

M18: B13 + 6% EVA-24


BBR Results (unaged binders)BBR Results (unaged binders)

BBR parameters vs. Polymer modification

-35

-30

-25

-20

-15

-10

-5

0Bc 3 XLl

3 XLr 6 XLl

6 XLr3 SBSl

3 SBSr

6 SBSl

6 SBSr

3 EVA6 EVA

3 EBA

6 EBABo 3 XLl

3 XLr6 XLl

6 XLr3 SBS l

3 SBSr

6 SBS l

6 SBSr

3 EVA6 EVA

3 EBA6 EBA

T is

o 30

0 &

0.3

(°C

)

Bc + XL

SBS EVA/BA

Bo + XL

SBS EVA/BA

–– Impact of polymer modification depends on Impact of polymer modification depends on ACAC & polymer natures& polymer natures

–– Positive in case of elastomer modifiers + X linking for both AC’Positive in case of elastomer modifiers + X linking for both AC’ss

ELASTOMER MODIFIED BINDERSSHRP Direct Tension SHRP Direct Tension -- unaged bindersunaged binders

Compared stress-strain curves

0

1

2

3

4

5

6

7

0 1 2 3

Strain (%)

Stre

ss (M

Pa)

EVA1

EVA2

EMA

EBA

SBS star

SB

SBXlinked

Bitumen

Bitumen

XLinked

Plastomers

Elastomers


POLYMER MODIFIED BINDERS PRODUCTION ISSUES

High shearMixer

Storage of PMB

Storage of PMB

Premixing

Dosage

Dosage

Polymer

Bitumen

Reagent


0

20

40

60

80

100

120

0 2 4 6 8 10 12 14 16 18

SBS content (%)

R&

B (

°C)

Phase Phase InversionInversion

Influence of SBS content on R&B & microstructureInfluence of SBS content on R&B & microstructure



•• Phase Phase SeparationSeparation whenwhen SBS SBS above above 55--7%7%

•• Stability at high Stability at high SBS content SBS content aroundaround 16% 16%

ELASTOMER MODIFIED BINDER ELASTOMER MODIFIED BINDER Storage stability (lab)Storage stability (lab)

% SBS% SBS

SBS m binderSBS m binder

1 3 6 9 12 16

Del

ta P

en (

0.1

mm

)

NeatStored - topStored - bottom


DemixtionDemixtion / Storage/ Storage«« Stokes’ rule» fault!Stokes’ rule» fault!

•• Emulsion Stability run by:Emulsion Stability run by:• Gravity (density of particles)• Viscosity = Force opposed to g

•• Particles SpeedParticles Speed•• dxdx//dtdt = 2r²(= 2r²(ρρ22--ρρ11)g/9)g/9ηη

r = particles radiusρ1= density of the external fluidρ2 = density of dropletsη = viscosity of the media

Stokes’ rule => Stokes’ rule => creaming when creaming when ρρ22 < < ρρ1 1

PmB = Emulsion where droplets = swollen polymer nodulesPmB = Emulsion where droplets = swollen polymer nodules


600 µm

450

µm

IR Spectroscopy= Global Analysis

Polybutadiene Band

γ C-H characteristic

IR Microscopy= Local Analysis

965 cm-1

FTIR MICROSCOPY

Mouillet et al, BLPC 2000


FTIR MICROSCOPY of PmB’s

SBS m Bitumen

600µm

450µ

m

965cm-1

1376 cm-1

γCH SBS band @ 965cm-1

δCH3 bitumen band @ 1376cm-1

EVA m Bitumen

600µm

450µ

m

νC-O EVA band @ 1242cm-1

δCH3 bitumen band @ 1376cm-1

1242cm-1

1600cm-1

Mouillet et al, BLPC 2000


ELASTOMER MODIFIED BINDERS

Influence of thermalInfluence of thermalhistory on propertieshistory on properties

Annealing R&B 58°CAnnealing R&B 58°C

A. Dony et al. BLPC 168, 7-8/90

Quench R&B 85°CQuench R&B 85°C

Annealing R&B 72Annealing R&B 72--82°C82°CQuench R&B 60°CQuench R&B 60°C

Fabrication R&B 88°CFabrication R&B 88°C

5% SBS PmB5% SBS PmB

180°C180°C

120°C120°C


Relationships between microstructureRelationships between microstructureand elastomer properties (SBS blends)and elastomer properties (SBS blends)

1

1

2

3

2

3Stress(MPa)

1

after A. Dony et al., Bull. Liaison Labo. P et Ch., 1990

5 % SBS - 3 Bitumens

100 200 3000 Elongation (%)

1

2

3

ELASTOMER MODIFIED BINDERSELASTOMER MODIFIED BINDERS



Change in Microstructure with chemical crosslinkingChange in Microstructure with chemical crosslinking

5% SB Crosslinked blend

5% SBPhysical Blend

((EpiEpi) Fluorescence Microscopy) Fluorescence Microscopy 50 microns



Microstructure of a Microstructure of a crosslinked PmB crosslinked PmB

(Styrelf®)

3 D Network3 D Network(N(N--hexane washed)hexane washed)

UV Fluorescence

0,34

0,36

FTIR Microscopy

Fine dFine dispersion of the in situ ispersion of the in situ crosslinked polymercrosslinked polymer


Elongation %

Str

ess

(daN

/cm

²)

0

0,5

1

1,5

2

2,5

3

0 100 200 300 400 500 600 700

PMB PMB XlinkedXlinked PMB PMB blendblend Base Base BitumenBitumen

Crosslinking effect

Direct Tension at 20°C, 500 mm/ minDirect Tension at 20°C, 500 mm/ min

ELASTOMER MODIFIED BINDERS ELASTOMER MODIFIED BINDERS

Elastomer PropertiesElastomer Properties


Low temperature properties

The ModeThe Mode--I Fracture TestI Fracture Test

Environmental chamber at Environmental chamber at --20°C20°CCutting of the rupture faces for Cutting of the rupture faces for CSEMCSEM or or ESEMESEM observationsobservations

TestTest

Speed = 0.6 Speed = 0.6 mm.minmm.min--11

T = T = --20°C20°C

KKICIC = failure load = failure load ×× f (span, crack length, sample dimensions)f (span, crack length, sample dimensions)

AfterAfter Lapalu et al, Eurobitume 2000Lapalu et al, Eurobitume 2000


Fracture mechanisms

Neat bitumen (KIC = 48 kPa.m1/2)

No topographic contrastNo topographic contrast

Brittle rupture Brittle rupture ðð low Klow KICIC

6% EVA-28 blend (KIC = 74 kPa.m1/2)ESEM observation at -5°C

50 µ

m

Polymer glassy at testing temperaturePolymer glassy at testing temperature

PolymerPolymer--rich particles pulledrich particles pulled--out without out without deformationdeformation

FFractureracture mechanism governed by mechanism governed by the (poor) adhesion between the (poor) adhesion between phases phases ðð low Klow KICIC


FRACTURE MECHANISMSFRACTURE MECHANISMS

Physical blendPhysical blend 4% SBS4% SBS**22 (K(KICIC = 107 = 107 kPakPa.m.m1/21/2))

44% SB % SB Crosslinked binder Crosslinked binder (K(KICIC = 113 = 113 kPakPa.m.m1/21/2))

CLSM observation at -165°C

PParticle pullarticle pull--out (crack deflection) without (crack deflection) with

Plastic Deformation of SBS NodulesPlastic Deformation of SBS Nodules

SBS in rubbery state SBS in rubbery state ðð High KHigh KICIC



PolymerPolymer--modified Bitumens modified Bitumens agingagingAfter L. Lapalu, JAfter L. Lapalu, J--P. Planche, V. Mouillet, P. Dumas, F. P. Planche, V. Mouillet, P. Dumas, F. Durrieu Durrieu –– Eurobitume Eurobitume Eurasphalt Eurasphalt Congress May 2004Congress May 2004

Collaboration between TOTAL and the LCPCCollaboration between TOTAL and the LCPC


Formation and association of polar molecules during ageing

Aged bitumens

0

30

60

90

1E+01 1E+03 1E+05 1E+07

BcBc after RTFOT + PAV Bo after RTFOT+PAV

G* (Pa)

1E+09

Plain bitumensPlain bitumens

ð More « elastic » behavior of the bitumenð Oxidation effect more pronounced for Bo


after ageing

0

30

60

90

1E+01 1E+03 1E+05 1E+07 1E+09G* (Pa)

Del

ta (

°)

Bc after RTFOT+PAVBc-EVA (6%) after RTFOT+PAVBc-SBS* (6%) after RTFOT+PAV

• After ageing, EVA is not oxidized but its compatibility with the oxidised bitumen matrix decreases, compared to SBS which keeps its reinforcement properties

Effect of polymer nature : EVA vs. SBSEffect of polymer nature : EVA vs. SBS


EVA EVA mBmB microstructure evolutionmicrostructure evolutionafter after DurrieuDurrieu et alet al

Before ageingBefore ageing

ÆÆ Phase inversion @ 6% EVAPhase inversion @ 6% EVA

ÆÆ EVAEVA swollen by slightly swollen by slightly condensed aromatics condensed aromatics substituted by aliphaticssubstituted by aliphatics7.6%

0.8%+ 6% EVA

7.6%7.6%7.6%

0.8%+ 6% EVA

7.6%

0.8%+ 6% EVA

7.6%7.6%

After RTFOT+PAV ageingAfter RTFOT+PAV ageing

ÆÆ Increase in EVA content in Increase in EVA content in the nodulesthe nodules

ÆÆ Stability of aromatics, but Stability of aromatics, but decrease in aliphatics and decrease in aliphatics and condensedcondensed

àà migration of the fraction migration of the fraction involved in EVA swelling to involved in EVA swelling to the surrounding matrixthe surrounding matrix

9.2%

0.4%+ 6% EVA

9.2%

0.4%+ 6% EVA

9.2%

0.4%+ 6% EVA

9.2%

0.4%+ 6% EVA

9.2%

0.4%+ 6% EVA

9.2%

0.4%+ 6% EVA

9.2%

0.4%+ 6% EVA


0

30

60

90

1E+01 1E+03 1E+05 1E+07 1E+09G* (Pa)

Bc-SBSlin (3%)Bc-Styr1 (3%)Bc-SBSlin (3%) after RTFOT+PAVBc-Styr1 (3%) after RTFOT+PAVBc-Styr1 (6%) after RTFOT+PAV

Effect of a crosslinking reactionEffect of a crosslinking reaction

• In case of crosslinked PmB's, the polymer and the matrix remain compatible after ageing •è elasticity on a large domain of temperature


Effect of the bitumen base: physical blendsEffect of the bitumen base: physical blends

In case of physical blends prepared out of oxidablebitumen (Bo), the compatibility between the polymer and the matrix is bad before and after ageingð Poor rheological properties

0

30

60

90

1E+01 1E+03 1E+05 1E+07 1E+09

G* (Pa)

Bo-SBSlin (6%)

Bo-SBSlin (6%) after RTFOT+PAV


PmB Aging: Impact on low temperature PmB Aging: Impact on low temperature propertiesproperties

Bc + XL SBSEVA/BA

Bo + XLSBS

EVA/BA

•• AC evolution is a function of its AC evolution is a function of its oxidabilityoxidability•• Influence of AC Influence of AC oxidabilityoxidability on the PmBon the PmB•• Positive effect of the X linked PmBPositive effect of the X linked PmB•• Negative impact of the EVA type polymersNegative impact of the EVA type polymers

0

5

10

15

20

D T

iso

(°C

)

Bc 3 XLl3 XLr

6 XLl6 XLr

3 SBSl

3 SBSr

6 SBSl

6 SBSr

3 EVA6 EVA

3 EBA

6 EBABo 3 XLl

3 XLr6 XLl

6 XLr3 SBS l

3 SBSr

6 SBS l

6 SBSr

3 EVA6 EVA

3 EBA6 EBA

D Tiso 300

D Tiso 300

BBR parameters evolution vs. RTFOT+PAV aging

D T iso 0.3


Conclusions : what to keep in mind ?Conclusions : what to keep in mind ?

•• Modified binders are complex organized molecular Modified binders are complex organized molecular systemssystems

•• They are highly dependent of polymerThey are highly dependent of polymer-- NatureNature

-- StructureStructure

-- Concentration … but …Concentration … but …

•• not only ! They also depend :not only ! They also depend :-- on bitumen nature and gradeon bitumen nature and grade

-- Mixing processMixing process

-- Addition of oils or crosslinking reagentsAddition of oils or crosslinking reagents

•• Finally, care should be given to characterization toolsFinally, care should be given to characterization tools-- relevance, artifacts, accuracy…relevance, artifacts, accuracy…


Thank you for your attentionThank you for your attention

•• Have a nice ride on a road paved with Polymer Have a nice ride on a road paved with Polymer Modified AsphaltModified Asphalt

•• Questions ?Questions ?

special features of polymer modified binders

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