Nano- and Micromechanics of Polymers - Structure Modification and Improvement of Properties

Table of Contents

Preface

List of Abbreviations

I Aim and methods

1 General Importance of Polymers and Trends

1.1 Relevance of Polymeric Materials

1.2 Materials Science Aspects

1.3 Molecular and Supramolecular Structures

1.3.1 Molecular Structures

1.3.2 Supramolecular Structures, Morphology

1.4 Polymer Modification

1.4.1 Copolymers

1.4.2 Polymer Blends

1.4.3 Particulate Composites

1.4.4 Short Fiber Reinforced Polymers

1.4.5 Conclusions

2 Methods and Investigation Techniques

2.1 Methods of Structure and Morphology Analysis

2.1.1 Macroscale Methods

2.1.1.1 X-Ray Diffraction Techniques (WAXS, SAXS)

2.1.1.2 Other Scattering Techniques

2.1.1.3 Spectroscopic Techniques and Thermal Methods

2.1.2 Local, Microscopic Methods

2.1.2.1 Optical Microscopy (OM)

2.1.2.2 Confocal Scanning Optical Microscopy

2.1.2.3 Scanning Electron Microscopy (SEM)

2.1.2.4 Transmission Electron Microscopy (TEM)

2.1.2.5 Atomic Force Microscopy (AFM)

2.1.2.6 Comparison of Microscopic Techniques

2.2 Methods of Nano- and Micromechanical Analysis

2.2.1 Macroscale Methods

2.2.1.1 Scattering (Diffraction) Methods

2.2.1.2 Interference Optics

2.2.1.3 Spectroscopic Techniques (Rheo-Optical Methods)

2.2.1.4 Other Techniques

2.2.2 Local (Microscopic) Methods

2.2.2.1 Overview

2.2.2.2 In-Situ Microscopy

2.3 Mechanical “Micro-Testing”

2.3.1 Mechanical Testing of Micro-Sized Specimens

2.3.2 Microindentation Tests

2.3.2.1 Imaging Method

2.3.2.2 Basic Aspects of Microindentation: Contact Geometry

2.3.2.3 Depth Sensing Measurements

II General mechanisms of deformation and fracture

3 Deformation Phenomena and Mechanisms

3.1 Basic Types of Mechanical Behavior

3.2 Influence of Specimen Size

3.3 Deformation Mechanisms

3.4 Molecular Parameters and Mechanisms

3.4.1 Molecular Mobility and Entanglements

3.4.2 Molecular Micro-Mechanisms

4 Crazing

4.1 The Phenomenon of „Craze“

4.2 Characteristics of Crazes

4.3 Variety of Craze Structures

4.4 Craze Initiation

4.4.1 Formation of Pre-Crazes

4.4.2 Transformation of Pre-Crazes into Fibrillated Crazes

4.5 Craze Growth and Fracture

4.5.1 Length Growth

4.5.2 Thickness Growth

4.5.3 Craze Fracture

4.6 Factors Influencing Craze Initiation and Growth

4.7 Structure Initiated Crazes

5 Fracture Phenomena and Mechanisms

5.1 Overview

5.2 Principles of Brittle Fracture of Polymers

5.3 Stress Concentrations at Particles and Voids

5.3.1 Soft Particles

5.3.2 Hard Particles

5.3.3 Thermal Stresses

5.3.4 Energetic Effects

5.3.5 Stress Concentration Effects in Different Particle/Void Arrangements

5.3.5.1 Particle/Void Size

5.3.5.2 Particle/Void Distance

5.4 Toughness Enhancing Mechanisms

5.5 Fracture Surface Analysis and Damage Analysis

III Main groups of polymer materials

6 Amorphous Polymers

6.1 Overview

6.2 Amorphous Homopolymers

6.2.1 Polystyrol (PS)

6.2.1.1 Deformation Characteristics

6.2.1.2 Modification of Crazes

6.2.2 Polymethylmethacrylate (PMMA)

6.2.3 Polyvinylchloride (PVC)

6.2.4 Polycarbonate (PC)

6.2.5 Other Amorphous Homopolymers

6.3 Copolymers

6.3.1 Styrene-Acrylonitrile-Copolymers (SAN)

6.3.2 Cyclic Olefin Copolymers (COC)

6.4 Comparison of Crazes

6.5 Resins, Thermosets

7 Semicrystalline Polymers

7.1 Overview

7.2 General Deformation Mechanisms

7.2.1 Brittle Behavior

7.2.1.1 Initiation of Brittle Fracture by Morphological Defects

7.2.1.2 Brittle Fracture of Low Molecular Weight Materials

7.2.1.3 Brittle Fracture at Low Temperatures

7.2.1.4 Environmental Stress Crazing/Cracking

7.2.1.5 Physical Ageing

7.2.2 Craze-Like Mechanisms

7.2.2.1 Crazing at Low Temperatures

7.2.2.2 Crazing at Brittle Fracture Above Tg,am

7.2.2.3 Environmental Crazing

7.2.2.4 Crazing under Plastic Deformation

7.2.2.5 Formation of Chevron Pattern

7.2.3 Ductile Behavior

7.2.3.1 Plastic Deformation of Spherulites

7.2.3.2 Deformation on the Amorphous/Lamellar Level

7.2.3.3 Strain Hardening and Self-Reinforcement

7.2.4 Deformation of Crystals and Lamellae

7.2.5 Self-Reinforcement and High Strength Materials

7.2.5.1 Oriented Structures by Melt Processing

7.2.5.2 Oriented Structures by Solution(Gel)-Spinning

7.3 Examples

7.3.1 Polyethylenes

7.3.1.1 Influence of Molecular Weight

7.3.1.2 Influence of Chain Architecture: Branching

7.3.1.3 Influence of Processing

7.3.2 Polypropylenes

7.3.2.1 Influence of Molecular Weight

7.3.2.2 Crystalline Modification

7.3.2.3 Influence of the Deformation Temperature

7.3.2.4 Additional Effects

7.3.3 Polyamides

7.3.4 Polyurethanes

7.3.5 Polyethylene Terephthalate (PET)

7.3.6 Syndiotactic Polystyrene

7.3.7 Fluoropolymers: PTFE, PVDF

7.3.8 Comparison of different polymers

8 Polymer Blends

8.1 Overview

8.2 Thermoplastic/Thermoplastic Blends

8.2.1 Blend Formation

8.2.2 Morphology

8.2.3 Micromechanical Properties

8.2.3.1 Blends of Amorphous Polymers

8.2.3.2 Blends of Amorphous and Semicrystalline Polymers

8.2.3.3 Blends of Semicrystalline Polymers

8.3 Rubbers and Elastomers

8.3.1 Overview

8.3.2 Typical Morphology

8.3.3 Micromechanical Behavior

8.4 Inclusion Yielding

9 Rubber Toughened Polymers

9.1 Overview

9.2 Morphology

9.3 Basic Micromechanical Mechanisms

9.3.1 Survey of Micromechanical Behavior

9.3.2 Rubber Particle Volume Content

9.3.3 Rubber Particle Modulus

9.3.4 Grafting Influence (Interfacial Bonding)

9.3.5 Particle Size

9.3.6 Additional Factors

9.4 Disperse Systems

9.4.1 Disperse Systems with Amorphous Matrix

9.4.2 Disperse Systems with Semicrystalline Matrix

9.5 Rubber Network Systems

10 Composites

10.1 Overview

10.2 Particle-Reinforced Polymer Composites

10.2.1 Morphology of Particle-Filled Polymers

10.2.2 Micromechanical Effects

10.2.2.1 Composites with a Tough Matrix (PE, PP)

10.2.2.2 Composites with a Stiff Matrix

10.2.2.3 Conclusion

10.3 Nanoparticle Polymer Composites

10.3.1 Overview and General Dependences

10.3.2 Micromechanical Effects in Different Classes of Nanocomposites

10.3.2.1 Zero-Dimensional Filler Nanoparticles (POSS)

10.3.2.2 One-Dimensional Carbon Nanotubes (CNT)

10.3.2.3 Two-Dimensional Layered Particles

10.3.2.4 Three-Dimensional Filler Particles

10.4 Fiber-Reinforced Polymer Composites

10.4.1 Overview

10.4.2 General Micromechanical Effects

11 Nanostructured Polymers

11.1 Overview

11.2 Block Copolymers

11.2.1 Introduction

11.2.2 Diversity in Morphologies and Properties

11.2.3 Micromechanical Behavior of Block Copolymers

11.2.4 Functional BCPs and Nanocomposites

11.2.5 Microdeformation Behavior in Block Copolymer/Polystyrene Blends

11.2.5.1 Blends Containing Macrophase-Separated PS Particles

11.2.5.2 Blends with Oriented Layers

11.2.5.3 Blends with Droplet Morphologies

11.2.6 Microhardness vs. Micromechanical Mechanisms

11.2.7 Mechanism of Chevron Formation

11.3 Coextruded Multilayered Polymers

11.3.1 Overview of Microlayered Composites and Coextrusion Technology

11.3.2 Structure-Property Correlations in Multilayered Composites Comprising Amorphous Polymers

11.3.3 Multilayered Crystalline/Amorphous Polymer Combinations

11.3.4 Multilayered Crystalline/Crystalline Polymer Combinations

11.4 Nanofibers

11.4.1 Overview

11.4.2 Electrostatic Spinning (Electrospinning)

11.4.3 Typical Fiber Structures

11.4.3.1 Fibers with Porous Structures

11.4.3.2 Fibers with Beads and Ribbon-Like Structures

11.4.3.3 Fibers with Helical and Twisted Structures

11.4.3.4 Fibers with Rough Surfaces

11.4.3.5 Fibers with Core Sheath Structures

11.4.4 Mechanical Properties of Polystyrene (PS) Nanofibers

11.4.5 Nanofibers – Nanocomposites

11.5 Conclusions

12 Special Forms and Applications

12.1 Overview, Special Forms

12.2 Hot Compacted Oriented Films/Fibers

12.2.1 Overview

12.2.2 Hot Compacted Oriented Fibers

12.2.3 Hot Compacted Oriented Films

12.2.4 Conclusions

12.3 Biomedical Polymers

12.3.1 UHMWPE

12.3.1.1 Morphology and Properties of UHMWPE

12.3.1.2 Application of UHMWPE in Hips and Knee Joints

12.3.2 Polymethylmethacrylate (PMMA)

12.3.3 Bioresorbable Polymers

12.3.4 Bone Substitutes

12.3.5 Electrospun Nanofibers

12.3.5.1 Nanofibrous Scaffolds for Tissue Engineering of Skin

12.3.5.2 Dentistry Applications

12.3.5.3 Scaffolds for Bone Tissue Engineering

12.4 Biopolymers

Index