Polymer Fracture

ISBN-13: 9783642696305 / Angielski / Miękka / 2011 / 456 str.

Hans-Henning Kausch

Opis

The first edition of this book had been written with the special aim to provide the necessary information for an understanding of the deformation and scission of chain molecules and its role in polymer fracture. In this field there had been an intense ac tivity in the sixties and early seventies. The new results from spectroscopical (ESR, IR) and fracture mechanics methods reported in the first edition had complemented in a very successful way the conventional interpretations of fracture behavior. The extremely friendly reception of this book by the polymer community has shown that the subject was timely chosen and that the treatment had satisfied a need. In view of the importance of a molecular interpretation of fracture phenomena and of the continued demand for this book which still is the only one of its kind, a second edition has become necessary. The aims of the second edition will be similar to those of the first: it will be at tempted to reference and evaluate completely the literature on stress-induced chain scission, now up to 1985/86. References on other subjects such as morphology, vis coelasticity, plastiC deformation and fracture mechanics, where the treatment was never meant to be exhaustive, have remained selective, but they have been updated."

Spis treści

1 Deformation and Fracture of High Polymers, Definition and Scope of Treatment.- References.- 2 Structure and Deformation.- I. Elements of the Superstructure of Solid Polymers.- A. Amorphous Regions.- B. Crystallites.- C. Superstructure.- 1. Spherulitic Structure.- 2. Oriented Lamellar Structures.- 3. Ultra-high Modulus Polymer.- 4. Globular Aggregates.- 5. Block Copolymers and Blends.- D. Characterization.- II. Deformation.- A. Phenomenology.- 1. Thermoplastic Polymers.- 2. Elastomers.- 3. Phenomenological Theory of Viscoelasticity.- B. Molecular Description.- III. Model Representation of Deformation.- References.- 3 Statistical, Continuum Mechanical, and Rate Process Theories of Fracture.- I. Introduction.- II. Statistical Aspects.- III. Continuum and Fracture Mechanics Approach.- A. Classical Failure Criteria.- B. Fracture Mechanics.- C. Continuous Viscoelastic Models.- IV. Rate Process Theories of Fracture.- A. Overview.- B. Eyring’ Theory of Flow.- C. Tobolsky-Eyring.- D. Rule of Cumulative Damage.- E. Early Theories of the Molecular Weight Dependency of Strength.- F. Effect of Volume Concentration of Primary Bonds.- G. Zhurkov, Bueche.- H. Hsiao-Kausch.- J. Gotlib, Dobrodumov et al.- K. Bueche-Halpin.- References.- 4 Strength of Primary Bonds.- I. Covalent Bonds.- A. Atomic Orbitals.- B. Hybridization.- C. Molecular Orbitals.- D. Multiple Bonds.- II. Bond Energies.- A. Electronic Energy and Heat of Formation.- B. Binding Energy of Exited States and Radicalized Chains.- 1. Electronic Excitation.- 2. Ionization.- 3. Radicalization.- III. Form of Binding Potential.- References.- 5 Mechanical Excitation and Scission of a Chain.- I. Stress-Strain Curve of a Single Chain.- A. Entropy Elastic Deformation.- B. Energy Elastic Chain Deformation Ill.- C. Non-Equilibrium Response.- II. Axial Mechanical Excitation of Chains.- A. Secondary or van der Waal’s Bonds.- B. Static Displacements of Chains Against Crystal Lattices.- C. Thermally Activated Displacements of Chains Against Crystal Lattices.- D. Chain Displacements Against Randomly Distributed Forces.- E. Dynamic loading of a chain.- III. Deexcitation of Chains.- References.- 6 Identification of ESR Spectra of Mechanically Formed Free Radicals.- I. Formation.- II. EPR Technique:.- A. Principles.- B. Hyperfme Structure of ESR Spectra.- C. Number of Spins.- III. Reactions and Means of Identification.- IV. Assignment of Spectra.- A. Free Radicals in Ground High Polymers.- B. Free Radicals in Tensile Specimens.- References.- 7 Phenomenology of Free Radical Formation and of Relevant Radical Reactions (Dependence on Strain, Time, and Sample Treatment).- I. Radical Formation in Thermoplastics.- A. Constant Rate and Stepwise Loading of Fibers.- B. Effect of Strain Rate on Radical Production.- C. Effect of Temperature.- 1. Apparent Energy of Bond Scission.- 2. Rate of Bond Scission.- 3. Concentration at Break.- D. Effect of Sample Treatment.- II. Free Radicals in Stressed Rubbers.- A. Preorientation, Ductility, and Chain Scission.- B. Cross-link Density, Impurities, Fillers.- III. Mechanically Relevant Radical Reactions.- A. Transfer Reactions.- B. Recombination and Decay.- C. Anomalous Decay.- D. Radical and Electron Trapping Sites.- References.- 8 The Role of Chain Scission in Homogenous Deformation and Fracture.- I. Small-Strain Deformation and Fracture of Highly Oriented Polymers.- A. Underlying Problems.- B. Loading of Chains before Scission.- C. Spatially Homogeneously Distributed Chain Scissions.- D. Formation of Microcracks.- E. Energy Release in Chain Scission.- F. Fatigue Fracture of Fibers.- G. Ultra High Strength Fibers.- II. Deformation, Creep, and Fatigue of Unoriented Polymers.- A. Fracture at small Deformations.- 1. Impact Loading.- 2. Fracture at Cryogenic Temperatures.- B. Failure under Constant Load (Creep and Long-Term Strength).- 1. General Considerations.- 2. Kinetic Theories.- 3. Creep Failure.- 4. Creep Crack Development.- C. Homogeneous Fatigue.- 1. Phenomenology and Experimental Parameters.- 2. Thermal Fatigue Failure.- 3. Wohler Curves.- 4. Molecular Interpretations of Polymer Fatigue.- 5. Fatigue-life Enhancement Through Surface Treatment.- D. Plastic Deformation, Yielding, Necking, Drawing.- E. Rupture of Elastomers.- III. Environmental Degradation.- A. Aspects to be Treated.- B. Chemical Attack on Stressed Samples.- 1. Ozone Cracking.- 2. Oxidation and Chemiluminescence.- 3. NOx, SO2.- 4. H2O, Other Liquids.- C. Additional Physical Attack on Stressed Samples.- 1. Physical Aging.- 2. UV.- 3. Particles and ?-Irradiation.- 4. Electric Fields.- References.- 9 Molecular Chains in Heterogeneous Fracture.- I. Linear Elastic Fracture Mechanics.- A. Stress Concentration.- B. Crack Tip Plastic Deformation.- C. Material Resistance and Crack Propagation.- D. Subcritical, Stable Crack Growth.- E. Critical Energy Release Rates.- F. Fracture Criteria.- G. Fracture Mechanics Specimen and Selected Values of Kc, Gc, KIc, GIc (Kcc, Gcc).- II. Crazing.- A. Phenomenology.- B. Initiation of Extrinsic Crazes.- C. Intrinsic Crazing and Stress-Whitening.- D. Molecular Interpretation of Craze Propagation and Breakdown.- E. Response to Environment.- III. Molecular and Morphological Aspects in Crack Propagation.- A. Fracture Surfaces and Molecular Mechanisms.- 1. Thermosetting Resins.- 2. Thermoplastics.- 3. Fibers.- B. Defects and Inherent Flaws.- C. Impact Fracture of Notched Specimens.- D. Fatigue Cracks.- E. Fracture-related Phenomena.- 1. Electro-Fracture Mechanics.- 2. Fracto-Emission.- 3. Mechano-Chemistry.- References.- 10 Fracture Mechanics Studies of Crack Healing.- I. Introduction.- II. Models of Adhesive and Cohesive Joint-Strength.- A. Adhesion and Tack.- B. Joint Strength of Thermoplastic Polymers.- C. Model Description.- III. Experimental Studies.- A. Uncrosslinked Thermoplastics.- 1. Experimental Procedure.- 2. Results and Observations.- 3. Estimation of Diffusion Coefficients.- 4. Reopening of Healed Cracks.- B. Crosslinked Thermoplastics.- 1. Experimental Procedure.- 2. Results of Mechanical Tests and Observations.- 3. Discussion.- C. Polymer Mixtures.- 1. Experimental Results.- 2. Conclusions.- D. General Conclusions Derived from Crack Healing Studies.- References.- Appendix Table A.1. List of Abbreviations of the Most Important Polymers.- Table A.2. List of Abbreviations not Referring to Polymer Names.- Table A.3. List of Symbols.- Table A.4. Conversion Factors.