Structure Formation in Polymeric Fibers

Contributors

Contents

Preface

1 Variations on a Theme of Uniaxial Orientation: Introductory Remarks on the Past, Present and Future of Fiber Formation

2 Structure Formation During Melt Spinning

2.1 Concepts and Theories

2.1.1 Introduction

2.1.2 An Engineering Analysis of the Process

2.2 Experimental Observations and Discussion

2.2.1 Polyolefins

2.2.2 Polyesters

2.2.3. Polyamides

2.2.4 Other Homopolymers

2.2.5 Copolymers Developed for Specialty Applications

2.2.6 Polymer Blends and Bicomponent Fibers

2.3 Concluding Remarks

Acknowledgments

2.4 References

3 Advances in the Control of Spinline Dynamics for Enhanced Fiber Properties

3.1 Introduction

3.2 Moving Beyond Imposed Limits as Take-Up Speeds Increase

3.2.1 The Dominant Forces

3.2.2 Cooling and Crystallization

3.2.3 Transient Effects

3.3 Recent Development Efforts and Achievements

3.3.1 Theoretical Tensile Strengths and the Potential for Vast Improvements

3.3.2 The Ideal One-Step Spinning Process

3.3.3 Patented Advances in Fiber Melt Spinning

3.4 The Preferred Route to Judicious Control of Spinline Dynamics

3.4.1 Judicious Control via Radical Change

3.4.2 The Response of Spinline Dynamics

3.4.3 Unprecedented As-Spun Fiber Properties

3.4.4 The Concept of Extended Chains and Enhanced Molecular Connectivity

3.5 Potential Applications and Future Development

3.6 References

4 Draw-Induced Structure Development in Flexible-Chain Polymers

4.1 Introduction

4.2 Overview of Stress-Strain-Structure Relationships

4.2.1 Modes of Deformation

4.2.2 Constant Extension Rate Deformation

4.2.3 Constant Force Deformation

4.3 Orientation-Induced Crystallization

4.3.1 General Concepts

4.3.2 The Case of Poly(ethylene terephthalate)

4.3.3 Other Polymers

4.4 Theory and Modeling

4.4.1 Stress-Strain-Orientation Behavior

4.4.2 Crystallization

4.4.3 Molecular Dynamics Simulations

4.5 Morphology

4.5.1 Range of Order

4.5.2 Three Phase Models

4.6 Structure-Property Relationships

4.6.1 Tensile Modulus, Strength, Yield, and Elongation at Break

4.6.2 Dimensional Stability

4.6.3 Penetrant Diffusion

4.7 High Performance Fibers

4.7.1 Apolar Polymers

4.7.2 Polar Polymers

4.8 References

5 Basic Aspects of Solution(Gel)-Spinning and Ultra-Drawing of Ultra-High Molecular Weight Polyethylene

5.1 Introduction

5.2 The Ultimate Stiffness and Strength of Flexible Polymers

5.2.1 The Ultimate Tensile Modulus

5.2.2 The Ultimate Tensile Strength

5.2.3 Infinite vs. Finite Chains

5.2.4 Chain Alignment, Orientation vs. Extension

5.3 Chain Orientation and Chain Extension

5.3.1 The Single Chain

5.3.2 An Ensemble of Chains

5.4 Drawing of Polyethylene in the Solid-State

5.4.1 Solid-State Drawing of Polyethylenes

5.4.2 Solution(Gel)-Crystallized Polyethylene

5.4.3 Solvent-Free Processing of UHME-PE; Nascent Reactor Powders

5.4.4 Modeling of the Drawing Behavior

5.4.5 Drawing Behavior of Other Polymer Systems

5.5 Properties of Polyethylene Fibers, 1-D vs. 3-D

5.5.1 Tensile Strength (1-D)

5.5.2 Polyethylene Fibers in Composites (3-D)

5.5.3 Miscellaneous Properties of UHMW-PE Fibers

5.6 Concluding Remarks

5. 7 List of Symbols and Abbreviations

5.8 References

6 Electrospinning and the Formation ofNanofibers

6.1 Introduction

6.2 Electrospinning Process

6.2.1 Jet Initiation and the Diameter of a Single Jet

6.2.2 Bending Instability and Elongation of the Jet

6.2.3 Diameter of Nanofibers

6.2.4 Observations of Electrospinning of Polyethylene oxide Solutions: Length ofthe Straight Segment, Flow Rate of the Solution, Current and Voltage

6.3 Nanofibers and Their Unique Properties

6.3.1 Beaded Nanofibers

6.3.2 Electrospun Poly (p-phenylene terephthalamide)

6.3.3 Composites with Nanofiber Reinforcement

6.3.4 Elastomeric Poly(styrene-butadiene-styrene) Nanofibers, Phase Miscibility

6.3.5 Carbon Nanofibers

6.3.6 Nanofibers for Biomedical, Filtration, Agricultural, and Outer-Space Applications

6.4 Acknowledgements

6.5 References

7 Fibers from Liquid Crystalline Polymers

7.1 Introduction: Liquid Crystalline Phases

7.2 Rheology in Liquid Crystalline Polymers

7.3 Fibers from Liquid Crystalline Polymers

7.4 Structure Formation and Properties of Liquid Crystalline Polymer Fibers from the Lyotropic Liquid Crystalline State

7.4.1 Molecular Parameters, Fiber Spinning, and Heat Treatments

7.4.2 PPTA Fiber Structure, Morphology, and Properties

7.4.3 PBZT and PBO Fiber Structure, Morphology, and Properties

7.5 Structure Formation and Properties of Liquid Crystalline Polymer Fibers from the Isotropic Solution State

7.5.1 Molecular Parameters, Fiber Spinning, and Heat Treatments

7.5.2 Organo-Soluble Aromatic Polyimide Fiber Structure, Morphology,and Properties

7.5.3 Technora Fiber Structure, Morphology, and Properties

7.6 Structure Formation and Properties of Liquid Crystalline Polymer Fibers from the Thermotropic State

7.6.1 Molecular Parameters, Fiber Spinning, and Heat Treatments

7.6.2 HBA/PET Copolyester Fiber Structure, Morphology, and Properties

7.6.3 HBA/HNA Copolyester Fiber Structure, Morphology, and Properties

7.6.4 Ekonol® Copolyester Fiber Structure, Morphology, and Properties

7.7 Concluding Remarks

7.8 References

8 Solvent Spun Cellulose Fibers

8.1 Structure and Properties

8.1.1 Introduction

8.1.2 Cellulose Structure

8.2 Fiber Formation

8.2.1 Introduction

8.2.2 Liquid Crystalline State

8.2.3 Direct Dissolution of Cellulose

8.2.4 Fiber Extrusion and Properties

8.3 Concluding Remarks

8.4 References

9 Carbon Fibers

9.1 Formation and Structure

9.1.1 Introduction

9.1.2 Carbon Fibers from PAN Precursors

9.1.3 Carbon Fibers from Pitch Precursors

9.2 Structure and Properties

9.2.1 Tensile Modulus

9.2.2 Tensile and Compressive Strength

9.2.3 The Structure of Carbon Fibers

9.2.4 Failure Mechanisms

9.2.5 Disorder in Carbon Fibers

9.2.6 Structure-Property Relations

9.3 References

10 Fibers from Electrically Conductive Polymers

10.1 Introduction

10.1.1 Polymer Conductivity

10.1.2 Measurement of Polymer Conductivity

10.1.3 Processing of Conductive Polymers

10.1.4 Fiber Formation

10.2 Fiber Formation from Emeraldine Base Polyaniline

10.2.1 Solution Spinning of Emeraldine Base Fiber

10.2.2 PANI Fiber Properties

10.2.3 Viscoelastic Characterization of PANI Spin Dopes

10.2.4 Thermal Characteristics of LEB PANI Fibers

10.3 Conclusion

10.4 Future Trends

10.5 References

11 Fibers from Polymer Blends and Copolymers

11.1 Introduction

11.2 Polymer Blends

11.2.1 Introduction

11.2.2 Miscibility

11.2.3 Multi-Phase Blends

11.2.4 Blends of Thermoplastics and Thermotropic Liquid Crystalline Polymers

11.3 Bicomponent Fibers

11.4 Fibers from Polymer Blends

11.5 Thermoplastic Fibers Reinforced with Thermotropic Liquid Crystalline Polymers

11.5.1 Fibers Produced via Simultaneous Melting of Blend Components

11.5.2 Fibers Generated Using the Dual Extrusion Process

11.5.3 Post Processing of Fibers Generated Using the Dual Extrusion Process

11.6 Copolymers

11.7 Elastomeric Fibers

11.8 References

12 Thermomechanical Processing: Structure and Properties

12.1 Introduction

12.2 Commercial Practice*

12.2.1 General Comments

12.2.2 Consumer Textiles

12.2.3 Tire Cord and Other Industrial Applications

12.3 Phenomenology of Thermomechanical Treatments

12.3.1 Mechanical Behavior During Processing; Creation of Internal Stress; Heat-Setting

12.3.2 The Development of Orientation of the Crystalline and Amorphous Substituents

12.4 Fiber Structure

12.4.1 Basic Structure

12.4.2 Crystal Transformation During Heat-Treatment

12.4.3 The Oriented Mesophase

12.5 Kinetics of Structure Development During Heat-Treatment

12.5.1 Effect of Orientation on the Crystallization Rate

12.5.2 In Situ Studies

12.5.3 Treat and Quench Investigations

12.6 Some Final Remarks

12.7 References

13 Microstructure Characterization

13.1 Wide Angle X-Ray Diffraction Analysis of Fibers

13.1.1 Introduction

13.1.2 Degree of Crystallinity

13.1.3 Degree of Orientation

13.1.4 Crystallite Size

13.1.5 Crystal Structure Determination

13.1.6 Aperiodic Scatter from Fibers of Random Copolymers

13.1.7 Transesterification in Blends of Copoly(HBA/HNA)

13.1.8 Non-Linearity and Distortions

13.1.9 References

13.2 Small-Angle Scattering

13.2.1 Introduction

13.2.2 Characteristics of SAS

13.2.3 Instrumentation

13.2.4 Data Analysis

13.2.5 Applications

13.2.6 Concluding Remark

13.2.7 References

13.3 Density, Birefringence, and Polarized Fluorescence

13.3.1 Crystallinity from Density

13.3.2 Molecular Orientation from Birefringence

13.3.3 Molecular Orientation from Polarized Fluorescence

13.3.4 References

13.4 Spectroscopic Methods: Infrared, Raman, and Nuclear Magnetic Resonance

13.4.1 Introduction

13.4.2 Infrared

13.4.3 Raman

13.4.4 Nuclear Magnetic Resonance

13.4.5 References

14 Fiber Formation and the Science of Complexity

14.1 Introduction

14.2 A Historical Account of Structural Complexity

14.2.1 The Early Fringed Micelle Models

14.2.2 The Common Working Model

14.2.3 Alternative Continuous Models

14.2.4 Other Complexities

14.3 The Science of Complexity

14.3.1 Far-from-Equilibrium

14.3.2 Characterizing Structure: Computer Graphics

14.3.3 Polymer Dynamics

14.3.4 Fractals

14.3.5 Kinetics of Nonhomogeneous Processes

14.3.6 Nonlinear Irreversible Thermodynamics

14.3.7 Chaos Theory

14.4 The Possible Role of Quantum Theory

14.4.1 Quantum Effects

14.4.2 Melt-Spun Fiber Formation

14.4.3 Clusters and Quantized Energy Levels

14.5 Conclusion: Scientific and Engineering Opportunity

14.6 References

Index