Mixing and Compounding of Polymers

Foreword

Contents

Part I: Mechanisms and Theory

1 Basic Concepts

2 Mixing of Miscible Liquids

2.1 Introduction

2.2 Continuum Analysis of Stretching

2.2.1 Deformation Analysis

2.2.2 Rate Analysis

2.2.3 Interface Stretching in Simple Flows

2.2.3.1 Simple Shear: Deformation Analysis

2.2.3.2 Simple Shear: Rate Analysis

2.2.3.3 Planar Elongation: Deformation Analysis

2.2.3.4 Planar Elongation: Rate Analysis

2.2.4 Stretching Behavior and Mixing Flows

2.3 Chaos and Chaotic Flows

2.3.1 An Example Flow

2.3.2 Poincaré Sections

2.3.3 Lyapunov Exponents

2.3.4 Periodic Points

2.4 Mixing in Chaotic Flows

2.4.1 Global Chaos

2.4.2 Universal Stretching Properties

2.4.2.1 Growth of Average Stretch

2.4.2.2 Global Stretching Distribution

2.4.2.3 Spatial Distribution of Stretch

2.4.2.4 Implications for Flow Selection

2.5 Other Considerations

2.5.1 Rheological Effects

2.5.2 Molecular Diffusion

2.6 Summary

Acknowledgements

References

3 Mixing of Immiscible Liquids

3.1 Introduction

3.2 Mixing Mechanisms

3.3 Distributive Mixing (Ca >> Cacrit)

3.3.1 Affine Deformation

3.3.2 Efficient Mixing: Stretching, Folding, and Reorienting

3.3.3 Static Mixers

3.3.3.1 Multiflux

3.3.3.2 Ross

3.3.3.3 Sulzer

3.3.3.4 Kenics

3.3.4 Optimization Kenics Mixers

3.3.4.1 Optimizing RL Designs

3.3.4.2 Optimizing for Non-Newtonian Fluids

3.3.4.3 Optimizing RR Designs

3.3.4.4 Scale-up: Use of Structure Radius and Scale of Segregation

3.3.4.5 Mapping the Structure

3.3.4.6 Conclusions

3.3.5 Dynamic Mixers

3.3.5.1 Co-Rotating Twin-Screw Extruders

3.3.5.2 Single Screw Extruders

3.3.5.3 The Rotational Arc Mixer (RAM)

3.3.6 Understanding Mixing: the Lid-Driven Cavity Flow

3.3.6.1 Geometry

3.3.6.2 Periodic Points

3.3.6.3 The Mapping Method

3.3.6.4 Accuracy of the Mapping Method

3.3.6.5 Optimization by Using the Mapping Method

3.3.6.6 Adding Inertia

3.3.6.7 3-D Cavity

3.4 Dispersive Mixing Ca ˜ Cacrit

3.4.1 Rayleigh Disturbances

3.4.2 Disintegration of Threads at Rest

3.4.3 Disintegration of Threads During Flow

3.4.4 Flow Classification

3.4.5 Drop Deformation and Breakup

3.4.6 Step-Wise Equilibrium versus Dynamic Breakup

3.4.6.1 Two Mechanisms

3.4.6.2 Plane Hyperbolic Flow

3.4.6.3 Simple Shear Flow

3.4.7 Theoretical Models for Drop Evolution

3.5 Coalescence and Influence of Surfactants

3.5.1 Collision of Drops

3.5.2 Film Drainage

3.5.2.1 Theoretical

3.5.2.2 Restrictions of the Drainage Models

3.5.2.2 Drainage Probability

3.5.2.3 Experimental

3.5.3 Coalescence Probability

3.5.4 Combination of Breakup and Coalescence

3.5.5 Influence of Surfactants on Deformation

3.5.5.1 Surface Tension Gradients

3.5.5.2 Equation of State

3.5.5.3 Drop Shapes

3.5.5.4 Modes of Drop Breakage

3.5.6 Influence of Surfactants on Coalescence

3.6 Polymer Blending in Practice

3.6.1 A Two-Zone Model

3.6.1.1 Principle

3.6.1.2 Numerical Approach

3.6.1.3 Effective Viscosity

3.6.1.4 Results

3.6.1.5 Influence of Material Parameters

3.6.1.6 Influence of Processing Conditions

3.6.2 Passage through a Die

3.6.3 Phase Inversion

3.6.4 Journal Bearing: a Second Model Flow

3.6.5 Dynamics of Mixing

3.7 Rheology and Morphology

3.7.1 Constitutive Modeling of Dispersive Mixtures

3.7.2 Diffuse Interface Modeling

3.8 Conclusions

APPENDIX 3.A: Determination of Interfacial Tension

Nomenclature

References

4 Dispersive Mixing of Solid Additives

4.1 Introduction

4.2 Continuum Dispersion Models

4.2.1 Agglomerate Structure and Cohesiveness

4.2.2 Models for Agglomerate Dispersion

4.3 Discrete Dispersion Models

4.4 Dispersion Mechanisms and Modelling Based on Experimental Observations

4.5 Concluding Remarks

Nomenclature

References

5 A Kinematic Approach to Distributive Mixing

5.1 Introduction

5.2 Kinematic Approach to Distributive Mixing

5.3 Application to Simple Flow Configurations

5.3.1 Simple Shear Flow

5.3.2 Pure Elongational Flow

5.4 Application to a Two-Dimensional Flow Configuration

5.5 Experimental Study of a Two-Dimensional, Nonstationary Flow

5.6 Application to Three-Dimensional Flow Configurations

5.6.1 Periodic Shearing Flow

5.6.2 Non-Stationary Flow within an Internal Mixer

5.7 Discussion

Nomenclature

References

6 Number of Passage Distribution Functions

6.1 Introduction

6.2 Theory of Number of Passage Distribution (NPD) Functions

6.3 NPD Functions in Batch and Flow Recirculating Systems

6.4 NPD Functions in Some Model Systems

6.4.1 Well-Stirred Batch Vessel with Recirculation

6.4.2 Plug Flow with Recirculation

6.4.3 Well-Stirred Continuous Mixing Vessel with Recirculation

6.5 Applications of NPD Functions to Dispersive Mixing

6.5.1 Dispersive Mixing

6.5.2 Modeling of Mixers

Acknowledgment

References

7 Mixing Measures

7.1 Introduction

7.2 Entropic Measures

7.2.1 Shannon Entropy

7.2.2 Renyi Entropies

7.2.2.1 Applications

7.2.3 Multi-Component Shannon Entropy

7.2.3.1 Application: Simultaneous Dispersive and Distributive Mixing Index

7.2.4 Modified Multi-Component Shannon Entropy

7.2.4.1 Applications to Extruders

7.2.4.2 Applications to Micromixers

7.2.5 Renyi Generalized Entropies and Fractal Properties

7.2.5.1 Applications

7.3 Summary

References

Part II: Mixing Equipment – Modeling, Simulation, Visualization

8 Flow Field Analysis of a Banbury Mixer

8.1 Introduction

8.2 Flow Simulations

8.2.1 Description of Method

8.2.2 Velocity Profiles and Pressure Distributions

8.3 Flow Field Characterization

8.3.1 Dispersive Mixing

8.3.2 Distributive Mixing

8.4 Summary and Conclusions

Nomenclature

References

9 CFD Simulations of Static Mixers: A Survey

9.1 Static Mixers in the Polymer Industry

9.2 Performance Criteria

9.2.1 Pressure Drop

9.2.2 Shearing Action

9.2.3 Mixing Performance

9.2.4 Mixing Homogeneity

9.2.5 CFD Methods

9.3 Numerical Modelling Principles

9.3.1 Simulation Flowchart

9.3.2 Equations of Change

9.3.3 Discretization

9.3.4 Solvers

9.3.5 Particle Tracking

9.4 Summary of the Main Hydrodynamic Predictions

9.4.1 Pressure Drop

9.4.2 Poincaré Maps

9.4.3 Residence Time Distribution

9.4.4 Overall Deformation and Shear

9.4.5 Transverse Flow

9.5 Summary of the Main Results on Mixing Evaluation

9.5.1 Segregation Scale

9.5.2 Intensity of Segregation

9.5.3 Chaos Theory

9.6 Mixer Performance Comparison

9.7 Other Mixing Evaluation Studies

9.8 Simulation Methods, Software Tools

9.9 Industrial Perspective and what the Future Holds

9.9.1 Single Phase Fluids

9.9.2 Multiphase Fluids

9.9.3 Multi-Scale Modeling

Nomenclature

References

10 Flow Visualization in Internal Mixers

10.1 Introduction

10.2 Historical Development of Internal Mixers

10.3 Flow Visualization

10.3.1 Flow Visualization by Various Sensors

10.3.2 Flow Visualization through Transparent Windows

References

11 Continuous Equipment Simulation – Single Screw

11.1 Introduction

11.2 General Equations for the Creeping Flows of Generalized-Newtonian Fluids

11.3 Geometrical Considerations and Approximations

11.4 Overview of Previous Work

11.5 Description of Applied Modeling Approaches

11.5.1 Two-Dimensional Formulation

11.5.2 Three-Dimensional Formulation

11.6 Predicted Results

11.6.1 Isothermal Flow of a Newtonian Fluid

11.6.2 Isothermal Flow of a Power-Law Non-Newtonian Fluid

11.6.3 Non-Isothermal Flow of Non-Newtonian Fluids

Nomenclature

References

12 Modeling Flow in Twin Screw Extrusion

12.1 Introduction

12.2 Modular Self-Wiping Co-Rotating Twin Screw Extruders

12.2.1 Technology

12.2.2 Flow in Individual Elements

12.2.3 Heat Balance

12.2.4 Melting

12.2.5 Composite Modular Machine Behavior

12.2.6 Global Machine Software

12.3 Tangential Counter-Rotating Twin Screw Extruders

12.3.1 Technology

12.3.2 Flow in Individual Elements

12.3.3 Heat Balance

12.3.4 Composite Modular Machine Behavior

12.4 Intermeshing Counter-Rotating Twin Screw Extruders

12.4.1 Technology

12.4.2 Flow in Individual Elements

12.4.3 Melting

12.4.4 Composite Modular Machine Behavior

12.5 Continuous Mixers

12.5.1 Technology

12.5.2 Flow Modeling

References

13 Continuous Equipment Simulation – Co-Kneader

13.1 Introduction

13.2 Machine Geometry and Working Principle

13.2.1 Screw Elements, Pins, and Barrel Liners

13.2.2 Melting

13.3 Modeling the Co-Kneader

13.4 Newtonian, Isothermal Analysis of Continuous Mixers

13.4.1 Twin-Screw Extruders

13.4.2 The Co-Kneader

13.5 Mixing

13.6 Experimental

13.6.1 Throughput versus Pressure Characteristic

13.6.2 Filled Length

13.6.3 Pressure Gradients

13.6.4 Residence Time Distribution

13.7 Nonisothermal, Non-Newtonian Analysis

13.8 Outlook

Nomenclature

References

14 Continuous Equipment Simulation – Mixing Devices

14.1 Static Mixers

14.2 Mixing Heads in Single Screw Extrusion

14.3 Conclusions

References

15 Continuous Process Visualization: Visual Observation, On-Line Monitoring, Model-Fluid Extrusion and Simulation

15.1 Introduction

15.1.1 Overview

15.2 Techniques for Visualization of Polymer Extrusion and Compounding

15.2.1 Experimental Simulation with a Simple Mixer and Real Material

15.2.1.1 Melting of Polymer Pellets

15.2.1.2 Melting of Polymer Powders

15.2.1.3 Melting of Polymer Blends

15.2.1.4 Melting of Polymer/Rubber Blends

15.2.1.5 Visualization of Morphological Transformations during Mixed Melting: the Phase Inversion Phenomenon

15.2.1.6 Visualization of Morphological Transformations during Mixed Melting: Direct Observation and Torque Monitoring of Miscible Blends with Extremely Low Viscosity Ratio (= 0.01)

15.2.2 Model Fluid Extrusion: Real Mixer with a Simple Fluid

15.2.2.1 Visualization of Flow in Extruders using Model Fluids

15.2.2.2 Visualization of Glass Fiber Dispersion in a Model Fluid

15.2.3 Processing with Continuous Equipment and Real Polymers

15.2.3.1 Visualization of the Extrudate at the Die Exit

15.2.3.2 Visualization of Fluid Flows in a Fixed Geometry

15.2.3.3 In-Line Sampling

15.2.3.4 On-Line Microscopy

15.2.3.5 Point Measurements: Characterization of Melting and Mixing Time with the Residence Time Distribution

15.2.3.6 Visualization of Solid Transport and the Onset of Melting by Direct Observation

15.2.3.7 Visualization of the Melting Zone by Direct Observation

15.2.3.8 Visualization and On-line Monitoring using Highly-Instrumented Extruders

15.2.3.9 Visualization of the Melting of Polymer Blends

15.2.3.10 Visualization of Phase Inversion during Polymer Blending

15.2.3.11 Visualization of Mixing of Polymer Pellets with Mineral Filler

15.2.3.12 Characterization of Energy Dissipation in the Melting Zone: Pulse Perturbation Method and Dynamic Monitoring

15.2.3.13 Characterization of the Twin Screw Extrusion Process from the Steady-State

15.3 Compounding Principles and Practical Examples

15.3.1 Melting Zone Extrusion and Mixing

15.3.1.1 Melting of Polymer/Polymer Blends

15.3.1.2 Melting of Polymer/Filler Blends

15.3.2 Mixing after Melting

15.3.3 Dispersive Mixing with Phase Inversion

15.3.3.1 Mixing of Plastic/Rubber Blends with High Viscosity Ratio (> 3.5)

15.3.3.2 Mixing of Plastic/Rubber Blends with Low Viscosity Ratio (< 0.28)

15.3.3.3 Mixing of Plastic/Rubber Blends with Extremely Low Viscosity Ratio (<< 0.1)

15.3.3.4 Mixing of Plastic/Rubber Blends: Blending with in situ Grafting

15.3.4 Melting and Mixing Dynamics in Extrusion

15.3.5 Unstable Flow during Single Screw Extrusion

15.3.6 Unstable Flow during Twin Screw Extrusion

15.3.7 Visualization and Monitoring Applied to Process Control

15.4 Summary

15.5 Concluding Remarks

References

16 Scale-Up of Mixing Equipment

16.1 Similarity

16.2 Systems

16.3 Dimensionless Groups

16.3.1 Global Treatment

16.3.2 Zone-Based Treatment

16.3.2.1 Melt Conveying Section

16.3.2.2 Melting Sections

16.3.2.2.1 Compact Solid Bed

16.3.2.2.2 Dispersive Melting

16.3.2.3 Solid Conveying Sections

16.3.2.4 Mixing in Melt Conveying Sections

16.3.2.4.1 Miscible Melts

16.3.2.4.2 Immiscible Melts

16.3.2.4.3 Solid/Melt Systems

16.4 Scale-Up, Scale-Down Rules

16.4.1 Continuous, Steady-State Processes

16.4.1.1 Melt Extruder and Melt-Dominated Smooth-Barrel Plasticizing Extruder

16.4.1.1.1 Identical Melt Output Temperatures and Identical Temperature Profiles over the Dimensionless Extruder Length

16.4.1.1.2 Different Temperatures for the Model and Main Machine

16.4.1.2 Rubber Extruder

16.4.1.3 Grooved Barrel Extruder

16.4.1.4 Co-Rotating Twin Screw Extruder

16.4.1.5 Counter Rotating Twin Screw Extruder

16.4.1.6 Non-Intermeshing Counter Rotating Twin Screw Kneader

16.4.1.7 Buss Kneader

16.4.1.8 Mixing Rolls

16.4.1.9 Mixing Elements

16.4.2 Discontinuous Processes

16.4.2.1 Internal Mixers

16.4.2.2 Mechanically Agitated Vessels

References

17 Scale-Down of Mixing Equipment: Microfluidics

17.1 Introduction

17.2 Mixing at Small Scales: Dimensionless Groups

17.3 Distributive Mixing at Small Scales

17.3.1 Passive versus Active Actuation

17.3.2 Passive Mixers: Design Options

17.3.3 Staggered Herringbone Mixer

17.3.4 Barrier-Embedded Static Mixers

17.3.5 Serpentine Channels

17.4 Active Mixers: Design Options

17.4.1 Neutral Beads

17.4.2 Magnetic Beads

17.4.3 Coupled Electrostatics and Hydrodynamics

17.4.4 Artificial Cilia

17.5 Dispersive Mixing at Small Scales

17.5.1 Experimental Observations

17.5.2 Boundary Integral Simulations

17.5.3 Small Deformation Theory

17.6 Conclusions

References

Part III: Compounding

18 Compounding (Theory and Practice)

18.1 Introduction

18.2 Types and Characteristics of Compounds

18.2.1 Polymer Blends

18.2.2 Polymer Formulations

18.2.3 Filled Polymers (Polymer Composites)

18.3 Compounding Practice

18.3.1 General

18.3.2 Polymer Blends and Polymer Formulations

18.3.3 Filled Polymers

18.3.3.1 Setting Up a Compounding Line

18.3.3.2 Low Aspect Ratio Fillers

18.3.3.3 High Aspect Ratio Fillers

18.3.3.4 Nanoclays

18.4 Concluding Remarks

Abbreviations

References

19 Solid Additives

19.1 Introduction

19.2 Synthesis and Chemical Properties of Amorphous Silica

19.2.1 Synthesis of Amorphous Silica

19.2.2 Chemistry and Properties of Silica Surfaces

19.2.3 Silica Mixing and Compounding

19.3 Morphology of Filler Agglomerates

19.3.1 Particle and Pore Size Distribution

19.3.2 Dispersibility of Fine Particle Agglomerates

19.3.3 The Fractal Nature of Filler Particulates

19.4 Filler Reinforcement

19.5 Concluding Remarks

References

20 Compatibilizers – Mechanisms and Theory

20.1 Introduction

20.2 Parameters Affecting Wetting, Dispersion, and Adhesion

20.3 Fillers – Surface Modification and Interfacial Agents

20.4 Compatibilizers for Polymer Blends

Abbreviations

References

21 Dispersion of Two-Dimensional Nanoparticles in Polymer Melts

Alejandra Reyna-Valencia and Mosto Bousmina

21.1 Introduction

21.2 Clay Particle Characteristics

21.2.1 Structure

21.2.1.1 Characterisation by X-Ray Diffraction

21.2.2 Surface Interactions

21.2.3 Intercalation by Organic Surfactants

21.3 Exfoliation Process

21.4 Stability of the Exfoliated Structure

21.5 Role of Exfoliation On Macroscopic Behavior

21.6 Special Case: Clay Dispersion in Multiphase Systems

21.7 Modeling of Rheological Behavior

21.8 Concluding Remarks

Acknowledgements

References

22 Effect of Mixing on Properties of Compounds

22.1 Types of Aggregation and Interaction between Particles

22.3 Determination of Dispersion and Dispersion Index

22.4 Mixing and Dispersion in Practice

22.4.1 Agglomerate Dispersion

22.4.1.1 Profile of Dispersed Phase

22.4.1.2 Effect of Mixing Conditions

22.4.1.3 Effect of Surface Treatment

22.4.2 Fiber Mixing

22.4.3 Mixing of Clay Nanocomposite

22.5 Dispersion and Properties

22.5.1 Mechanical Properties

22.5.1.1 Effect of Agglomerate Dispersion

22.5.1.2 Effect of Interface

22.5.2 Electrical Properties

22.5.3 Properties of Clay Nanocomposites

22.5.4 Properties of Other Nanocomposites

22.6 Summary

Nomenclature

References

Part IV: Mixing Practices

23 Internal Mixers

23.1 Introduction

23.2 Mixing Mechanism of Internal Mixer

23.2.1 Structure of Internal Mixer

23.2.2 Mixing Steps for Mixing of Polymers and Fillers

23.2.3 Dispersion Mechanism of Fillers

23.3 Studies of Mixing Mechanism by Model Tests

23.3.1 Two-Dimensional and Three-Dimensional Model Tests

23.3.2 Improvement of Rotors by Model Tests

23.4 Development of New Rotor for Internal Mixers

23.4.1 Rotor in Tangential Type Internal Mixer

23.4.1.1 Four-Wing Rotor (4WN)

23.4.1.2 ST Rotor

23.4.1.3 Tangential Type 6-Wing Rotor (6WI)

23.4.2 Development of Rotors for Intermeshing Mixers

23.4.2.1 Intermeshing Mixers

23.4.2.2 VIC Mixer

23.4.2.3 Partial Intermeshing Mixer

23.5 Improvement of Internal Mixers

23.6 Summary

References

24 Mixing in Single-Screw Extruders

24.1 Introduction

24.2 Laminar Mixing in Melt Conveying

24.2.1 Effect of Reorientation

24.2.2 Backmixing

24.2.2.1 Cross Sectional Mixing and Axial Mixing

24.2.2.2 Residence Time Distribution

24.2.2.3 RTD in Screw Extruders

24.2.2.4 Methods to Improve Backmixing

24.2.2.5 Conclusions

24.2.3 Chaotic Mixing

24.3 Mixing Devices in Extrusion

24.3.1 Distributive Mixing Elements

24.3.1.1 The Vortex Intermeshing Pin (VIP) Mixer

24.3.1.2 Description of the VIP Mixer

24.3.1.3 Experimental Results

24.3.2 Dispersive Mixing Sections

24.3.2.1 Design of Dispersive Mixing Devices

24.3.3 Using the TSE Mixing Mechanism in Single Screw Extruders

Nomenclature

References

25 Mixing Practices in Co-Rotating Twin Screw Extruders

25.1 Introduction

25.2 Building Blocks for Mixing

25.2.1 Extruder Geometry

25.2.2 Element Geometry

25.3 Typical Process Mixing Tasks

25.3.1 Polymer/Polymer

25.3.2 Polymer/Low Aspect Ratio Filler

25.3.3 Elastomer – Elastomer/Low Aspect Ratio Filler

25.3.4 Polymer/High Aspect Ratio Filler (Fiber)

25.3.5 Polymer/Nano Scale Filler

25.3.6 Polymer/Low Viscosity Additives

25.4 Summary

References

26 Intermeshing Twin Screw Extruders

26.1 Outline

26.2 Total Compounding System

26.2.1 Outline of the Total System

26.2.2 Typical Machine Specifications and Output Capacities

26.2.3 Extrusion Performance Simulation

26.2.3.1 Melting Mechanism Analysis

26.2.3.2 Twin Screw Extrusion Characteristics Simulation

26.3 Compounding Applications

26.3.1 Inorganic Filler Compounding

26.3.2 Glass-Fiber Compounding

26.3.2.1 Short Glass Fiber Compounding

26.3.2.2 Long Glass Fiber Compounding and Molding

26.3.3 Polymer Nano-Composite Compounding

26.3.4 Polymer Blending

26.3.4.1 Miscible Polymer Blending

26.3.4.2 Immiscible Polymer Blending

26.4 Reactive Extrusion

26.4.1 Advantages of Reactive Extrusion

26.4.2 Typical Chemical Reactions

26.4.3 Recycling Applications

26.4.3.1 PET Direct Extrusion

26.4.3.2 PET Modification for Producing Foamed Sheet

26.4.3.3 Combination of Reactive Processing and Injection Molding

26.5 Devolatilization

26.5.1 Effects of Water Addition

26.5.2 High Concentration Devolatilization

References

27 Reactive Compounding

27.1 Introduction

27.2 Free Radical Grafting of Monomers onto Polymers

27.2.1 Overall Reaction Scheme

27.2.2 Free Radical Grafting in a Batch Mixer

27.2.2.1 Effect of Comonomers

27.2.2.2 Effect of Temperature

27.2.2.3 Effect of Mixing

27.2.3 Free Radical Grafting in a Twin Screw Extruder

27.2.3.1 Effect of Screw Design

27.2.3.2 Effect of Plastication/Melting

27.2.3.3 Effect of Feeding Mode

27.2.4 Recent Developments

27.2.4.1 Fractional Feeding

27.2.4.2 Concept of Nano-Reactors

27.3 Reactive Blending

27.3.1 General Features of Morphology Development

27.3.2 Reactive Blending in Batch Mixers or Analogues

27.3.2.1 Effect of the Copolymer Formation Kinetics

27.3.2.2 Effect of Mixing Time

27.3.2.3 Effect of Mixing Intensity

27.3.3 Reactive Blending in Screw Extruders

27.3.3.1 Non-Reactive versus Reactive Blends

27.3.3.2 Effect of Screw Configuration

27.3.3.3 Effect of the Compatibilizer Content

27.3.3.4 Adverse Effect of Mixing

27.3.4 One-Step versus Two-Step Reactive Blending

27.3.5 Comparison of in situ Compatibilization to Separate Copolymer Addition

27.3.6 Polymerized Blends

27.3.6.1 Intractable Engineering Plastics/Monomer Systems

27.3.6.2 Nano-Blends

27.4 Compounding of Polymer Nanocomposites

27.4.1 Multi-Scale Structures of Montmorillonite (MMT)

27.4.2 Mechanisms of Dispersion of MMT in Polymers

27.4.3 Factors Affecting the Rate and Scale of Dispersion of MMT in Polymers

27.4.4 Water-Assisted MMT Dispersion in Polymers

27.5 Summary

References

28 Continuous Mixers

28.1 Introduction

28.2 Structure and Principles of Operation

28.2.1 Solids Conveying

28.2.2 Melting

28.2.3 Mixing

28.2.4 Devolatilization

28.2.5 Pumping

28.3 Modeling

28.3.1 Circumferential Flow

28.3.2 Global Flow Models

28.3.3 Scale-Up Considerations

28.4 Rotor Design

28.4.1 Single-Stage Rotors

28.4.2 Two-Stage Rotors

28.5 Conclusion

List of Symbols

Abreviations

References

Subject Index