Prototype of virtual experiments

AMUSEAMUSE( Advanced Materials design Using Simulation Engines )

Hiroyasu TasakiJCII, Doi project

4. Mar. 2002

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

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

10µm

20nm

Ultimate Goal : Seamless Zooming !!

1cm

100nm

5nm

10µm

20nm COGNAC

SUSHI

MUFFIN

AMUSEAMUSE 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)

4. Mar. 2002

Important properties ofPP materials

- 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.

PP material designstiffness

toughness

c-axis

morphology

crystallite orientation

lamella structure

2.

future work

MUFFIN

COGNAC

SUSHI3.

1.

interfacial property

bulk elasticity

4. Mar. 2002

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 from

SUSHI to MUFFIN.3. Interfacial strength of PP/elastomer blends.- Generate the initial structure of polymer chain at an

interface 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).

AMUSEAMUSE

4. Mar. 2002

Lamella structure of semi-crystalline polymers Kodama

Calculation of the chain conformation in an amorphous layer (SUSHI).crystal amorphous crystal

0 d x

loop

bridgetail

0.75

0.76

0.77

0.78

0.79

0.8

0.81

0.82

0.02

0.03

0.04

0.05

0.06

0.07

5 5.5 6 6.5 7 7.5 8

totalloop

bridge

tota

l, lo

op bridge

d

Loop bridge fraction for infinite chain.

Parameters :Long period, Crystallinity, Molecular weight, Molecular weight distribution,Branching ...

4. Mar. 2002

Lamella structure of semi-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,.

Molecular dynamics simulation of the stretching of the lamella structure.

elongation

4. Mar. 2002

Lamella structure of semi-crystalline polymers Aoyagi

bead-spring model4 chains with 1200 beads

0.000

0.001

0.010

0.100

1.000

0 20 40 60 80 100

LoopLoop(SCF)

nl(m)

m

0.0000

0.0001

0.0002

0.0003

0.0004

0.0005

0 50 100 150 200

BridgeBridge(SCF)

nb(m)

m

0.70

0.75

0.80

0.85

0.90

0.95

1.00

1.05

0 5 10 15 20

Density

Z

crystallayer

amorphouslayer

Density profile

Loop

Bridge

4. Mar. 2002

Simulation Experiments

Stress-strain curve

Lamella structure of semi-crystalline polymers Shoji

L. Barish, J. Appl. Polymer Sci., 6, 617 (1962)

4. Mar. 2002

Bulk elasticity ofPP/elastomer blends Noda & Sasaki

Zooming from SUSHI to MUFFIN.

volume fraction of component A

SUSHIMorphology of PP/elastomer blends

MUFFINElastic modulus of the material having some morphology

4. Mar. 2002

Dispersed

Bicontinuous

Bulk elasticity ofPP/elastomer blends Noda

The only minor component is shown.

WI & NI

Veenstra, H., et al., Polymer, 41, 1817 (2000)

4. Mar. 2002

c-axis(molecular axis)

High orientational case E1,ave :1100 (MPa)(anisotropic) E2,ave : 58 (MPa)

Random case(isotropic) Eave : 550 (MPa)

Calculation of elasticity of oriented crystallite.

Anisotropic elastic moduli used forthe calculation are obtained by COGNAC.

crystallite

1

2

Bulk elasticity ofPP/elastomer blends Noda

4. Mar. 2002

Interfacial strength of PP/elastomer blends Yokomizo & Aoyagi

SUSHICalculate the chain conformation at the interface.

COGNACCalculate the interfacial strength at the interface

MUFFINPredict the mechanical properties of bulk materialreflecting the physical properties at an interface.

Interfacial thickness, Chain conformation

Stress-Strain curve

Toughness etc. (Future work)

MUFFINPredict PP/elastomer morphology under shear.

Structure formation under shear

4. Mar. 2002

Interfacial strength of PP/elastomer blends Aoyagi

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

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

0.00

0.20

0.40

0.60

0.80

1.00

0 2 4 6 8 10 12 14 16

SCFMD

phi_A

Z

SUSHI1D calculation

Neuman boundary condition

interface

4. Mar. 2002

χAB = 0.25thin interface

χAB = 0.10thick interface

Effects of polydispersity on the interfacial properties.AB polymer blendsmonodisperse : A100 / B100polydisperse : A55, 550 / B55, 550

interfaceshort chain

long chain

interface

Interfacial strength of PP/elastomer blends Yokomizo

4. Mar. 2002

Interfacial strength of PP/elastomer blends Yokomizo

Effects of polydispersity on the stress-strain behavior.

monodispersethick interface

polydispersethick interface

monodispersethin interface

4. Mar. 2002

Interfacial strength of PP/elastomer blends Yokomizo

Simulations Experiments

monodispersethick interface

monodispersethin interface

polydispersethick interface

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

4. Mar. 2002

SummaryBy combining the simulation programs on a platform, practical simulation has become possible to study many phenomena which were difficult to deal with by the conventional method.

COGNACCOGNAC

SUSHISUSHI

MUFFINMUFFIN

Elastic modulus ofsingle component

Multi-phase structure

Interaction parameters

4. Mar. 2002

Endwledgements:

hemical Innovation Institute (JCII) by the New Energy and elopment Organization (NEDO) under METI's

that

AcknoThis work is supported by the national project, which has been entrusted tothe Japan CIndustrial Technology DevProgram for the Scientific Technology Development for IndustriesCreates New Industries.