Dynamic Mechanical Analysis a Practical Introduction Book

Author's Preface xi Foreword to the First Edition xiii Foreword to the Second Edition xv Acknowledgments xvii Author xix Chapter 1 An Introduction to Dynamic Mechanical Analysis 1
1.1 A Brief History of DMA 1
1.2 Basic Principles 2
1.3 Sample Applications 4
1.4 Creep-Recovery Testing 9
1.5 Aggressive Environments 10 Notes 12 Chapter 2 Basic Rheological Concepts: Stress, Strain, and Flow 15
2.1 Force, Stress, and Deformation 15
2.2 Applying the Stress 17
2.3 Hooke's Law: Defining the Elastic Response 20
2.4 Geometry, Sample Shape, and Aspect Ratio 24
2.5 Liquid-Like Flow or the Viscous Limit 25
2.6 Another Look at Stress-Strain Curves 28
2.7 Appendix: Conversion Factors 32 Notes 35 Chapter 3 Rheology Basics: Creep-Recovery and Stress Relaxation 37
3.1 Creep-Recovery Testing 37
3.2 Models to Describe Creep-Recovery Behavior 40
3.3 Analyzing a Creep-Recovery Curve to Fit the Four-Element Model 41
3.4 Analyzing a Creep Experiment for Practical Use 44
3.5 Creep Ringing 45
3.6 Other Variations on Creep Tests 45
3.7 Superposition: The Boltzmann Principle 48
3.8 Retardation and Relaxation Times 49
3.9 Structure-Property Relationships in Creep-Recovery Tests 50
3.10 Stress Relaxation Experiments 51
3.11 Constant Gauge Length Tests 53 Notes 54 Chapter 4 Thermomechanical Analysis 57
4.1 Theory of Thermomechanical Analysis 57
4.2 Experimental Considerations with TMA Samples 59
4.3 Expansion and CTE 61
4.4 Flexure and Penetration 64
4.5 Dilatometry and Bulk Measurements 65
4.6 Mechanical Tests 65
4.7 PVT Relationship Studies 67 Notes 68 Chapter 5 Dynamic Testing and Instrumentation 71
5.1Applying a Dynamic Stress to a Sample 71
5.2 Calculating Various Dynamic Properties 74
5.2.1 Calculation from Deformation and Phase Lag 75
5.2.2 Calculating Properties from a Measured Stiffness 76
5.3 Instrumentation for DMA Tests 76
5.3.1 Forced Resonance Analyzers 76
5.3.2 Stress and Strain Control 77
5.3.3 Axial and Torsional Deformation 79
5.3.4 Free Resonance Analyzers 79
5.4 Fixtures or Testing Geometries 81
5.4.1 Axial 83
5.4.1.1 Three-Point and Four-Point Bending 84
5.4.1.2 Dual and Single Cantilever 85
5.4.1.3 Parallel Plate and Variants 86
5.4.1.4 Bulk 87
5.4.1.5 Extension/Tensile 87
5.4.1.6 Shear Plates and Sandwiches 87
5.4.2 Torsional 88
5.4.2.1 Parallel Plates 88
5.4.2.2 Cone-and-Plate 89
5.4.2.3 Couette 89
5.4.2.4 Torsional Beam and Braid 90
5.5 Sample Handling Issues 90
5.6 Calibration Issues 91
5.7 Dynamic Experiments 92 Notes 93 Chapter 6 Time and Temperature Scans Part I: Transitions in Polymers 95
6.1 Time and Temperature Scanning in the DMA 95
6.2 Transitions in Polymers: Overview 98
6.3 Sub-T[subscript g] Transitions 101
6.4 The Glass Transition (T[subscript g] or T[subscript alpha]) 103
6.5 The Rubbery Plateau, T[subscript alpha]* and T[subscript ll] 106
6.6 The Terminal Region 110
6.7 Frequency Dependencies in Transition Studies 112
6.8 Applications 114
6.9 Time-Based Studies 117
6.10 Conclusions 118 Notes 119 Chapter 7 Time and Temperature Scans Part II: Thermosets 123
7.1 Thermosetting Materials: A Review 123
7.2 Studying Curing Behavior in the DMA: Cure Profiles 127
7.3 Photocuring 132
7.4 Modeling Cure Cycles 133
7.5 Isothermal Curing Studies 133
7.6 Kinetics by DMA: The Roller Model and Other Approaches 134
7.7 Mapping Thermoset Behavior: The Gillham-Enns Diagram 137
7.8 Quality Control Approaches to Thermoset Characterization 138
7.9 Postcure Studies 140
7.10 Conclusions 141 Notes 142 Chapter 8 Frequency Scans 145
8.1 Methods of Performing a Frequency Scan 145
8.2 Frequency Effects on Materials 147
8.3 The Deborah Number 155
8.4 Frequency Effects on Solid Polymers 155
8.5 Frequency Effects During Curing Studies 158
8.6 Frequency Studies on Polymer Melts 158
8.7 Normal Forces and Elasticity 159
8.8 Master Curves and Time-Temperature Superposition 161
8.9 Transformations of Data 167
8.10 Molecular Weight and Molecular Weight Distributions 169
8.11 Conclusions 171 Notes 171 Chapter 9 Unusual Conditions and Specialized Tests 175
9.1 UV Studies 175
9.1.1 UV Photocures 177
9.1.2 UV Photodegradations 178
9.2 Humidity Studies 179
9.2.1 Equilibration Times 181
9.2.2 Effects of Humidity in the DMA 182
9.3 Immersion 182
9.3.1 Effects of Solvent on Instrumentation and Measurement 183
9.3.2 DMA in Solution 184
9.4 Hyphenated Techniques 186
9.5 Modeling Other Mechanical Tests 187 Notes 188 Chapter 10 DMA Applications to Real Problems: Guidelines 191
10.1 The Problem: Material Characterization or Performance 191
10.2 Performance Tests: To Model or to Copy 191
10.3 Choosing a Type of Test 192
10.4 Characterization 194
10.5 Choosing the Fixture 194
10.6 Checking the Response to Loads 197
10.7 Checking the Response to Frequency 197
10.8 Checking the Response to Time 197
10.9 Checking the Temperature Response 198
10.11 Putting It Together 199
10.12 Verify the Results 199
10.13 Supporting Data from Other Methods 200
10.14 Appendix: Sample Experiments for the DMA 201
10.14.1 TMA Experiments 201
10.14.2 Stress-Strain Scans 201
10.14.3 Creep-Recovery Experiments 201
10.14.4 Stress Relaxation 202
10.14.5 Dynamic Strain Sweeps 202
10.14.6 Dynamic Temperature Scans 202
10.14.7 Curing Studies 202
10.14.8 Frequency Scans 202 Notes 202 Index 205