Prototype of virtual experiments

AMUSE( Advanced Materials design Using Simulation Engines )Hiroyasu Tasaki
JCII, Doi projectOutline- Introduction- Lamella structure of semi-crystalline polymers- Bulk elasticity of PP/elastomer blends- Interfacial strength of PP/elastomer blends- Summary

4. Mar. 2002

Introduction
AMUSE is an exploratory project conducting a virtual experimentsby cooperating two or more simulation programs and the platform.
Test material : Polypropylene(PP) materials (PP/elastomer blend)
1cm10µm

10µm
MUFFIN

100nm
SUSHI

20nm
20nm
T. Nomura, T. Nishio, H. Tanaka, K. Mori,
Japanese Journal of Polymer Science and Technology,
vol.52, N0.2, pp.90-96 (1995))
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COGNAC

5nm

Ultimate Goal : Seamless Zooming !!

Important properties ofPP materials
stiffness

PP material design
toughness- Lamella structures of alternating crystalline and amorphous
phases.
- Tie molecules related to the molecular weight and tacticity
of polypropylene.
- Orientation of the polypropylene crystallite.
- Morphology of a polypropylene/elastomer blend.
- Conformation at a polypropylene/elastomer interface.
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2.

MUFFINbulk elasticity

morphology3.

SUSHI

future work

interfacial property
c-axiscrystallite orientation

1.

lamella structure

COGNACAMUSE
1. Lamella structure of semi-crystalline polymers.
- Generate the initial semi-crystalline lamella structure
by zooming from SUSHI to COGNAC.
- Predict the elasticity of the PP crystal using the model of amorphouslayer.
2. Bulk elasticity of PP/elastomer blends.
- Predict the elastic modulus of PP materials by zooming fromSUSHI to MUFFIN.
3. Interfacial strength of PP/elastomer blends.
- Generate the initial structure of polymer chain at aninterface by zooming from SUSHI to COGNAC.
- Study the interfacial properties of PP/elastomer blends.
- Predict the mechanical properties of bulk materials
using the physical properties at the interface (future work).
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Lamella structure ofsemi-crystalline polymers

KodamaCalculation of the chain conformation in an amorphous layer (SUSHI).
crystalamorphous

crystalLoop bridge fraction for
infinite chain.

loop

0.07

0.82
0.81

dParameters :Long period, Crystallinity,
Molecular weight,
Molecular weight distribution,
Branching ...
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x0.79

0.050.78

0.04
bridge

0.77

0.03

0.76
0.75

55.5

66.5
d7

7.5

80.02

bridge0totalloop

0.8

bridgetotal, loop

tail0.06

Lamella structure ofsemi-crystalline polymers Shoji & Aoyagi
Generating lamella structure by using a method of COGNAC.
6nm

COGNAC can generate a lamella
structure of semi-crystalline
polymer using the conformation
distribution of loop and bridge
obtained by SUSHI,.
elongation

Molecular dynamics simulationof the stretching of the lamellastructure.
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Lamella structure ofsemi-crystalline polymers

Aoyagi1.000

Loop0.100nl(m)bead-spring model
4 chains with 1200 beads

Loop
Loop(SCF)

0.010

0.001

0.000
020

406080100

Density profile

m0.0005

1.05

BridgeBridgeBridge(SCF)

0.0004

1.00
0.95

nb(m)

Density

0.00030.0002amorphous
layer

0.90

crystal
layer

0.85
0.80

0.00010.75

0.00000.70

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50100m

150

200

0

510Z

1520

Lamella structure ofsemi-crystalline polymers

Shoji

Stress-strain curve
Simulation

Experiments

L. Barish, J. Appl. Polymer Sci., 6, 617 (1962)
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Bulk elasticity of
PP/elastomer blends

Noda & Sasaki

Zooming from SUSHI to MUFFIN.

SUSHI
Morphology ofPP/elastomer blends
volume fraction of component A

MUFFIN
Elastic modulus of thematerial having somemorphology
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Bulk elasticity of
PP/elastomer blends

Bicontinuous

Noda

WI & NI

Dispersed
The only minor component is shown.
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Veenstra, H., et al., Polymer, 41, 1817 (2000)

Bulk elasticity of
PP/elastomer blends

Noda

Calculation of elasticity of oriented crystallite.
Anisotropic elastic moduli used forthe calculation are obtained by COGNAC.
c-axis(molecular axis)
12High orientational case E1,ave :1100 (MPa)(anisotropic) E2,ave : 58 (MPa)
Random case(isotropic) Eave : 550 (MPa)
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crystallite

Interfacial strength of
PP/elastomer blends Yokomizo & Aoyagi
Structure formation under shear
MUFFIN
Predict PP/elastomer morphology under shear.

Interfacial thickness, Chain conformation
SUSHI
Calculate the chain conformation at the interface.

Stress-Strain curve
COGNAC
Calculate the interfacial strength at the interface

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MUFFIN
Toughness etc. (Future work)
Predict the mechanical properties of bulk materialreflecting the physical properties at an interface.

Interfacial strength of
PP/elastomer blends

AoyagiA method of generating the initial structure of polymer chainsat an interface by zooming from SUSHI to COGNAC.
SUSHI

COGNAC

1D calculation
Neuman boundary condition

bead-spring model(1bead=1SCF segment)
Staggered reflective boundary condition

1.00
SCF
MDphi̲A

0.80
0.60
0.40
0.20

interface
0.00
02

4

68

Z

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10121416

Interfacial strength of
PP/elastomer blends

Yokomizo

Effects of polydispersity on the interfacial properties.
AB polymer blendsmonodisperse : A100/ B100
polydisperse : A55, 550 / B55, 550
interfaceinterfaceshort chainχAB = 0.10
thick interfaceχAB = 0.25
thin interface

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long chain

Interfacial strength of
PP/elastomer blends

Yokomizo

Effects of polydispersity on the stress-strain behavior.
polydisperse
thick interface
monodisperse
thick interface

monodisperse
thin interface

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Interfacial strength of
PP/elastomer blends
Simulations

Yokomizo
Experiments

polydisperse
thick interface

monodisperse
thick interface

monodisperse
thin interface
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Kimberly A. Chaffin, Frank S. Bates, et al.,Science 2000, 288, 2187-2190.

Summary
By combining the simulation programs on a platform, practicalsimulation has become possible to study many phenomena
which were difficult to deal with by the conventional method.
Elastic modulus of
single component
Multi-phase structure

MUFFINSUSHI
COGNACInteraction parameters
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Acknowledgements:
This work is supported by the national project, which has been entrusted tothe Japan Chemical Innovation Institute (JCII) by the New Energy andIndustrial Technology Development Organization (NEDO) under METI's
Program for the Scientific Technology Development for Industries that
Creates New Industries.

End4. Mar. 2002