Nanostrength Block Copolymers for Epoxy Toughening … · Block Copolymers for Epoxy Toughening ... CTBN / TP Core-Shell Nanostrength 11 1 ~ 5 µm 0.1 ~ 0.8 µm 10 ~ 100 nm. Block

Nanostrength®

Block Copolymers for Epoxy

Toughening100 nm

PABu

PMMA

PMMA / Epoxy

Nanostrength® for epoxy toughening

Arkema Overview Nanotechnology Platform at Arkema

NANOSTRENGTH® NANOSTRENGTH Block Copolymers for Epoxy – Value Drivers

Epoxy Toughening with NANOSTRENGTH ®

Range of properties achievable using NANOSTRENGTH®

How it works Application Specific Properties- Composites and Adhesives

2

Arkema 2007 overviewSales by region

Europe (excl. France)

39%

Sales: €5.7 bn ($8.5B)

Capital employed: €3 1 bn

39%

France18%

North America

25%

Sales per year

Capital employed: €3.1 bn

Capex: 4% of sales

18%Row

5%Asia13% 2007

R&D: 3% of sales

15 200 employees

In € bn

5.52 5.67 5.70

2005 2006 2007

15,200 employees

3

2005 2006 2007

R&D accelerates product innovationOverview (2007)

3% of sales

1 350 researchers

R&D by segment

12%Vi l

Breakthrough

1,350 researchers

Near 100 joint projects with universities

6 R&D centers

Portfolio around 5,700 patents

12%

12%

51%

25%

Vinyl Products

PerformanceProducts

Industrial Chemicals

2005

Chemicals

Recent breakthroughsRecent breakthroughs

4

Nanotechnology Platform at Arkema

Our customers :Compounds, Thermosets,

Pigments, Engineering resins,Paints, Coatings,

Adh iAdhesives,…Functionalized Specialty Block CRP* initiator

&FlexiBloc®

Copolymers

FlexiBloc®

CRP*

&

Reactive Block Copolymer

Block Copolymers

macroinitiator

5

p y

Nanotechnology Platform at Arkema

Block copolymers for epoxy toughening

6

Classical vs. Controlled Free Radical

Classical Radical Polymerization

Controlled Radical Polymerization

No control of termination

“Living” chain ends experience reduced

Wide polydispersitiesRandom sequencing

f it

experience reduced terminationReduced

of monomer units polydispersitiesBlock copolymers

possiblepossible

7

Complete Control of Block Structure

Block copolymers

Classical Block copolymersClassical Block copolymers

Incompatibility between blocks organization at the nanometer scale

Randomcopolymer

Diblockcopolymer

ABA triblockcopolymer

ABC triblockcopolymer

scale

8

Nanostrength® Triblock Polymers

Controlled Radical Polymerization (CRP)ABA, AB

P l [(M th l) th l t ] b l (B t l A l t ) b l [(M th l) th l t ]

Functional comonomers can be added (AA, MAA, PEGMA, HEMA,…)

Poly[(Methyl)methacrylate] -b- poly(Butyl Acrylate) -b- poly[(Methyl)methacrylate]Poly[(Styrene] -b- poly(Butyl Acrylate) -b- poly[(Styrene]

Anionic polymerizationSBM

Outstanding control of molecular weight, molecular weight

polyStyrene -b- polyButadiene -b- poly[(Methyl)methacrylate]

9

g g gdistribution, composition, chain architecture, functionalization

Block Copolymers for Epoxy Toughening Structural Adhesives (Automotive, Industrial, Assembly, Wind

Energy, Electronics …)

Coating (Solvent, Powder,…)

Composites (Aerospace, Sports and Leisure,…)p ( p , p , )

Epoxy compounds

Nanostrength® is suited for every application that needs an increase in resistance to crack propagation while maintaining Tg and Modulus of the systems.

Due to the unique nanostructuration achievable with Nanostrength®, it is possible to achieve identical toughnessto competiti e modifiers (CTBN) b t sing red ced loading

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to competitive modifiers (CTBN) but using reduced loading levels.

Block Copolymers for Epoxy TougheningAdvantages of Nanostrength®:

• Toughening with little loss of Tg or Modulus

• Outstanding toughening at lower loading due to unique modifier morphologies

• Ease of Processing- additive dissolves in epoxy resinEase of Processing additive dissolves in epoxy resin

• Nanoscale self-assembled particles allow for toughening of:1. Thin adhesive bond lines

2. Thin coatings

3. Composites with small inter-fiber spacing

Core-ShellCTBN / TP NanostrengthNanostrength

11

0.1 ~ 0.8 µm1 ~ 5 µm 10 ~ 100 nm

Block Copolymers for Epoxy Toughening

Low Tg systems: DGEBA + JeffamineTM T403Low Tg systems: DGEBA + JeffamineTM T403

Loading Level K1C G1C Tg K1C G1C TgM53 CTBN

0% 0.76 183 92 0.76 183 922.5% 1.66 1873 925% 1.71 1933 92

7.5% 1.95 2348 9310.00% 2.78 3437 97 1.98 1640 85

Superior toughening at equivalent loadings Equivalent toughening at lower loadings

12


Intermediate Tg systems: DGEBA + DICYIntermediate Tg systems: DGEBA + DICY

Loading Level K1C Tg K1C Tg0% 0.88 +- 0.1 148.1 0.88 +- 0.1 148.1

M52N CTBN

2.50% 1.32 +- 0.12 146.4 1.03 +- 0.12 TBD5.00% 1.64 +- 0.08 144.2 1.32 +- 0.12 139.1

10.00% 1.82 +- 0.11 135.4 1.62 +- 0.08 129.2

Dicyandiamide (Dicy) is hardener representative of:

Adhesives- Adhesives

- Sports and Leisure composites

- Coatings

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- Coatings

A Self-assembling Nanotechnology

- Affinity between epoxy monomers and PMMA- Repulsion between epoxy monomers and the middle block(s)

Nanophase separation of PBuA blocks:

DGEBAM - A - M

Nanophase separation of PBuA blocks:

PABu

PMMA

PMMA / E

PABu

PMMA / Epoxy

14

PMMA

PMMA / Epoxy

Toughening of epoxy systems

• Many mechanisms contribute to epoxy toughness :

•• Shear yieldingShear yielding•• Shear yieldingShear yielding• Multiple crazing• Crack pinning• Crack bridgingCrack bridging• Crack deflection• ….

T h i i th fl ibili tiToughening is more than flexibilization. Flexibilization lowers the modulus of the material to decrease brittleness (CTBN - flexibilizer) by reacting to the backbone of the epoxy. Nanostrength® (and

h ll ) i t i d l hil t h i

Pearson (1993)H Y d Ki l h A J J M t S i 27 2763 (1992)

core shells) maintain modulus while toughening.

15

Huang, Y., and Kinloch, A.J., J. Mater. Sci., 27, 2763 (1992).


The most efficient mechanisms to toughen are system & condition dependant:

• Low Tg systems, high T° or low speed testing conditions: Shear yielding Matrix network has enoughMatrix network has enough

mobility to activate plasticity

•• High Tg systemsHigh Tg systems, low T° or high speed testing conditions:: Multiple crazing Crack bridging C k i i

Matrix network too cross-linked to activate plasticity

Crack pinning Crack deflection

p y

R A Pearson "An overview of organic toughening agents for epoxy resins" ERFD Spring 2000 Conference

16

R.A. Pearson, An overview of organic toughening agents for epoxy resins , ERFD Spring 2000 Conference, April 16-18, 2000, San Antonio, TX


Existing tougheners have specific toughening mechanisms: Liquid reactive rubbers shear yieldingq y g Thermoplastics crack bridging, pinning & deflection

Acrylic block copolymers: all mechanisms

Shear Yielding (cavitation of the rubber phase)

Nanoscale modifiers lead to high density of shear band

Acrylic block copolymers: all mechanisms

Nanoscale modifiers lead to high density of shear band formation

Unique morphologies lead to better toughening

Crack Bridging

Crack Pinning (strong matrix adhesion)

17

Crack Deflection

Toughening of epoxy systemsCavitation of nanodomains

18


Modifier morphology in cured epoxy dependent on:

•Crosslinking/Resin chemistry

•Block Copolymer Chemistry

M51, M52, M53: PMMA-block-PBuA-block-PMMA

DGEBA + M DEA DEGBA + Jeffamine

19

DGEBA + M-DEA DEGBA + Jeffamine T403


Block Copolymer Chemistry dictates Modifier Morphology

MAM exp1

5µm

DGEBA + DDS

5µm

Ref +10% MAM exp1

+10% MAM exp2

+10% MAM M22N

MAM exp2

3µm

M22N

2µm

Development of functionalized grades to further improve nanostructuration with all types of epoxy systems:

M22N or M52N: PMMA/DMA block PBuA block PMMA/DMA

20

M22N or M52N: PMMA/DMA-block-PBuA-block-PMMA/DMA


Modifier Morphology dictates Properties

DGEBA J ff i T403Low Tg systemsLow Tg systems

DGEBA + Jeffamine T403

M22N gives M53 gives M22N gives excellent nanostructuration for perfect

“spider web” agglomeration for superior t h ip

transparency toughening

Neat Epoxy M22N M53

K1C 0.76 1.54 2.78

21

G1C 183 880 3437


Plastic Deformation of the samples with block copolymers

DGEBA + Jeffamine T403Low Tg systemsLow Tg systems

250

200

250

150

e (N

)

Neat

100Forc 10% M53

10% CTBN

0

50

22

00 0.2 0.4 0.6 0.8 1 1.2

Displacement (mm)


Balance of properties:

S i DGEBA+ Jeffamine T403Fluidity at 80°CSuperior toughening with some viscosity penalty with 10%

DGEBA+ Jeffamine T403

0.6

0.8

1.0

Fluidity at 40°CTgpenalty with 10% M53

or 0.0

0.2

0.4

Fluidity at 40 CTg

Neat

Equivalent viscosity and toughening, E GIC

10% CTBN10% M532.5% M53

g g,improved Tg and modulus at ¼ of the loading KIC

23


Loading Level K1C Tg K1C TgM52N CTBN

Intermediate Tg systems: DGEBA + DICYIntermediate Tg systems: DGEBA + DICY

0% 0.88 +- 0.1 148.1 0.88 +- 0.1 148.12.50% 1.32 +- 0.12 146.4 1.03 +- 0.12 TBD5.00% 1.64 +- 0.08 144.2 1.32 +- 0.12 139.1

10.00% 1.82 +- 0.11 135.4 1.62 +- 0.08 129.210.00% 1.82 0.11 135.4 1.62 0.08 129.2

M52N gives worm-like micelle Nanospherical micelles for

K1C= 1.54 K1C= 1.82

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structure for excellent toughening

pperfect transparency (exp. grade)


Fluidity at 40°C NeatCTBN 10%

Balance of properties:

Superior CTBN 10%M52N 10%M52N 5%

Superior toughening and Tg at equivalent loading

Fluidity at 80°CTg

loading

Equivalent qtoughening and viscosity with enhanced Tg at

E KIC

½ of the loading

25

Nanostrength® for Epoxy Toughening

160 C cureKIC

(MPa.m0.5)

T (°C)

Reference 0.72 108

Even greater advantages with Nanostrength®

in more “toughenable” DICY cured systems

•lower cure temperatureReference 0.72 10810% M52N 2.4 11810% CTBN 1.88 112 •higher Epoxy Equivalent Weight (EEW) resin

DGEBA/DICYstudy done with Ray Pearson Lehigh University

Neat

10%M52Nstudy done with Ray Pearson, Lehigh University

2

2.5

10%M52N

10% CTBN X 810% CTBN X13

1

1.5

K1C

0

0.5

180 190 200 210 220 230 240 250

26

180 190 200 210 220 230 240 250

DGEBA EEW


Impact Testing

DGEBA + Dicyandiamide (DICY)High Speed Impact Resistance

2.5

3

•More than 2X

1.5

2

Abs

orbe

d (J

) improvement in impact energy (CEAST Fractovis dart drop) with block copolymers

0.5

1

Ene

rgy

A with block copolymers.

•10-30% improvement in peak force at break.

0Neat M52N- 10% CTBN-10%

27

Toughening of epoxy composites

High Tg systemsHigh Tg systems RTM6

DGEBA + M-DEA 1 0Fluidity at 100°C

Loading Level K1C G1C Tg0% 0.74 258 170

% 1 01 530 168

M53

DGEBA M DEA

0.6

0.8

1.0

10.00% 1.01 530 168

DGEBA + DDS0.0

0.2

0.4Fluidity at 120°CTg

Neat

Loading Level K1C G1C Tg0% 0.9 283 229

10.00% 1.08 428 227

M52NNeatM51M52PSU

Excellent toughening and good maintenance of Tg

E KIC

M51, M52: Lower MW MAM

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meets RTM specs for viscosity

Toughening of epoxy adhesives

25

30a)

Neat

Nanostrength-10%

CTBN-10%

15

20

Stre

ngth

(MPa CTBN 10%

5

10

Lap

Shea

r S

0DICY Jeffamine D230 DETA

Study done by Rescoll laboratories

•No detrimental effect on adhesion in DICY and polyetheramine (Jeffamine D230) cured epoxies while maintaining Tg and improving fracture toughness

•Significant improvement in lap shear strength in diethylene triamine (DETA)

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Significant improvement in lap shear strength in diethylene triamine (DETA) cured epoxies


Dissolution of block copolymers in epoxy

•Block copolymers Dissolution time in low Mw epoxy resinwill dissolve in epoxy resin; no need for dispersion

p y

40

45

5090°C135°C

•Block copolymers dissolve quickly at elevated temperatures with25

30

35

40

e (m

in)

temperatures with minimal shear

•Transparency of solution does not 10

15

20Tim

e

always indicate dissolution!0

5

M52 M53 M52N

30

SBM Block Copolymers for Epoxy Toughening

PMMA block gives excellent compatibility to epoxy systems which are less polar (similar to

Neat

Epoxy E21 E41 DGEBA/Jeffamine

Tg 92 97 TBDwhich are less polar (similar to non-functionalized MAM)

Butadiene block has a lower Tg (-70 C) than butylacrylate (-40

Tg 92 97 TBDK1C 0.76 2.91 TBD G1C 183 3940 TBD

DGEBA/MDEA T 170 176 177

( ) y y (C) so improved toughening at lower temperatures possible

Higher differences in chi t ll f h t

Tg 170 176 177K1C 0.74 0.93 1.08 G1C 258 TBD 418

Phenolic Novolac parameters allows for shorter (lower MW) block copolymers to still nanostructure -> Lower viscosity products possible

Tg 175 TBD 180 K1C 0.63 TBD 0.86 G1C 152 TBD 282

y p p

31


AdvantagesAdvantages: S i T h i

DrawbacksDrawbacks:N d di l hi h Superior Toughening to

competitive products Equivalent toughening at much

lower loadings ($ advantages)

Need to dissolve at high temperature in epoxy

Increase of viscosity (mitigated by use at lower loadings)lower loadings ($ advantages)

Versatile block copolymer chemistry allows for the proper grade to be selected for given

by use at lower loadings)

g gepoxy systems

Balance of Properties: Limited loss of Tg and Modulus

High reproducibility (controlled by Thermodynamic)/ no need for dispersion

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Commercial Nanostrength® GradesSBM gradesE21 - Medium MW with high butadiene content, good for structural

applications; excellent toughening with PMMA friendly cross-linking agents (Jeffamine, MDEA)

E41 - Low MW with medium butadiene content, low increases in viscosity, good for electronic or viscosity sensitive applications

MAM gradesM52 medium MW low viscosityM52- medium MW, low viscosityM53-High molecular weight, excellent toughening with PMMA friendly

cross-linking agents (Jeffamine, MDEA)M52N Functionalized MAM; best toughening with PMMA unfriendly crossM52N- Functionalized MAM; best toughening with PMMA unfriendly cross-

linking agents (DICY, DDS); composite and adhesive applicationsM22N- Highly functionalized MAM for excellent compatibility and

nanostructuration (transparent applications or highly polar systems)

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nanostructuration (transparent applications or highly polar systems)

Documents

Nanostrength Block Copolymers for Epoxy Toughening … · Block Copolymers for Epoxy Toughening ... CTBN / TP Core-Shell Nanostrength 11 1 ~ 5 µm 0.1 ~ 0.8 µm 10 ~ 100 nm. Block