Dynamics in Polymer Blends and Polymer-solvent Blends Close to the Glass Transition

Dynamics in Polymer Blends and Polymer-solvent Blends Close to the Glass Transition PDF Author: Grégoire Julien
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

Get Book Here

Book Description
In this work, we propose a model for describing the dynamics in polymer blends or polymer-solvent blends close to and below Tg. The model is solved on a 2D lattice corresponding to spatial scales from 10 nm up to a few micrometers and incorporate the heterogeneous nature of the dynamics at the scale of a dynamic heterogeneity (3-5 nm). In case of polymer blends, we apply this model to study phase separation close to and below Tg upon cooling, and rejuvenation in miscible range upon heating. In the course of phase separation, we observe slow structures forming in coexistence with faster ones. In the same time, the global dynamics of the system slows down and domains grow like the logarithm of the time. During rejuvenation, we observe that morphologies melt much faster the elapsed time required to build them during aging. In the case of polymer-solvent blends, the system is put in contact with a solvent reservoir and is at temperatures far below the pure polymer glass transition. We consider situations where the activity of the solvent reservoir is varied in order to describe either films drying or swelling. Our model allows for explaining case-II diffusion in the context of the plasticisation of a glassy polymer by penetrating solvent during swelling. Regarding the process of film drying, we show that films up to 1 micrometer thick can be completely dried. When drying a thicker film, we show that a glassy crust may appear on the free surface, as shown experimentally.

Dynamics in Polymer Blends and Polymer-solvent Blends Close to the Glass Transition

Dynamics in Polymer Blends and Polymer-solvent Blends Close to the Glass Transition PDF Author: Grégoire Julien
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

Get Book Here

Book Description
In this work, we propose a model for describing the dynamics in polymer blends or polymer-solvent blends close to and below Tg. The model is solved on a 2D lattice corresponding to spatial scales from 10 nm up to a few micrometers and incorporate the heterogeneous nature of the dynamics at the scale of a dynamic heterogeneity (3-5 nm). In case of polymer blends, we apply this model to study phase separation close to and below Tg upon cooling, and rejuvenation in miscible range upon heating. In the course of phase separation, we observe slow structures forming in coexistence with faster ones. In the same time, the global dynamics of the system slows down and domains grow like the logarithm of the time. During rejuvenation, we observe that morphologies melt much faster the elapsed time required to build them during aging. In the case of polymer-solvent blends, the system is put in contact with a solvent reservoir and is at temperatures far below the pure polymer glass transition. We consider situations where the activity of the solvent reservoir is varied in order to describe either films drying or swelling. Our model allows for explaining case-II diffusion in the context of the plasticisation of a glassy polymer by penetrating solvent during swelling. Regarding the process of film drying, we show that films up to 1 micrometer thick can be completely dried. When drying a thicker film, we show that a glassy crust may appear on the free surface, as shown experimentally.

Encyclopedia of Polymer Blends, Volume 1

Encyclopedia of Polymer Blends, Volume 1 PDF Author: Avraam I. Isayev
Publisher: John Wiley & Sons
ISBN: 3527805184
Category : Science
Languages : en
Pages : 330

Get Book Here

Book Description
A complete and timely overview of the topic, this volume of the encyclopedia imparts knowledge of fundamental principles of polymer blends. Each article is uniformly structured for easy navigation, containing the latest research & development and its basic principles and applications.

Encyclopedia of Polymer Blends, Volume 3

Encyclopedia of Polymer Blends, Volume 3 PDF Author: Avraam I. Isayev
Publisher: John Wiley & Sons
ISBN: 3527653988
Category : Science
Languages : en
Pages : 528

Get Book Here

Book Description
A complete and timely overview of the topic, this Encyclopedia imparts knowledge of fundamental principles and their applications for academicians, scientists and researchers, while informing engineers, industrialists and entrepreneurs of the current state of the technology and its utilization. The most comprehensive source on polymer blends available on the market Offers a complete and timely overview of the topic Each article presents up to date research & development on a topic and its basic principles and applications, integrates case studies, laboratory and pilot plant experiments, and gives due reference to published and patented literature Equips academics, scientists and researchers with knowledge of fundamentals principles and their applications, and informs the engineers, industrialists and entrepreneurs about the state of the art technology and its applications

Dynamics and Rheology of Miscible Polymer Blends

Dynamics and Rheology of Miscible Polymer Blends PDF Author: Jeffrey Charles Haley
Publisher:
ISBN:
Category :
Languages : en
Pages : 624

Get Book Here

Book Description


Polymer Blends and Composites

Polymer Blends and Composites PDF Author: John A. Manson
Publisher: Springer Science & Business Media
ISBN:
Category : Science
Languages : en
Pages : 544

Get Book Here

Book Description
1. Homopolymer Structure and Behavior.- 1.1. High Polymers.- 1.2. Molecular Size and Shape.- 1.2.1. Chain Conformation.- 1.2.2. Chain Entanglement.- 1.3. Molecular Structure.- 1.3.1. Configurations of Polymer Chains.- 1.3.2. Stereo and Geometrical Isomerism.- 1.3.3. Random Branching.- 1.3.4. Nonrandom Branching.- 1.3.5. Crosslinking.- 1.4. Crystallinity and Order.- 1.4.1. Fringed Micelle Model.- 1.4.2. Folded-Chain Single Crystals.- 1.4.3. Extended-Chain Crystals.- 1.4.4.Spherulites.- 1.5. Mechanical Response: Elasticity and Viscoelasticity.- 1.5.1. Molecular and Segmental Motion.- 1.5.2. Modulus-Temperature Behavior.- 1.5.3. Five Regions of Viscoelastic Behavior.- 1.5.4. Rubberlike Elasticity.- 1.5.5. Dynamic Mechanical Spectroscopy.- 1.5.6. Stress-Relaxation and Creep Behavior.- 1.5.7. Time-Temperature Relationship.- 1.6. Energetics and Mechanics of Fracture.- 1.6.1. General Approach to Fracture.- 1.6.2. Energy Balance in Fracture.- 1.6.3. Viscoelastic Rupture of Elastomers.- 1.7. Mechanical Testing of Polymers.- 1.7.1. Stress-Strain and Fracture Behavior.- 1.7.2. Impact Strength.- 1.7.3. Fatigue.- Appendix A. Polymer Synthesis.- Appendix B. Basic Mechanical Properties and Relationships.- Bibliography of Polymer Books and Journals.- 2. General Behavior of Polymer Mixtures.- 2.1. Methods of Mixing Polymer Pairs.- 2.1.1. Polymer Blends.- 2.1.2. Graft Copolymers.- 2.1.3. Block Copolymers.- 2.1.4. Interpenetrating Polymer Networks (IPN's).- 2.2. Interdiffusion.- 2.3. Nomenclature.- 2.4. Electron Microscopy.- 2.5. The Incompatibility Problem.- 2.5.1. Thermodynamics of Mixing.- 2.5.2. Polymer-Polymer Phase Diagrams.- 2.6. Bulk Behavior of Two-Phase Polymeric Materials.- 2.6.1. Glass Transitions.- 2.6.2. Modulus-Temperature Behavior of Model Polyblends.- 2.6.3. Stress-Relaxation Behavior.- 2.6.4. The Takayanagi Models.- 2.6.5. Free Volume Model.- 2.6.6. Other Models.- 2.6.7. Morphology-Modulus Interrelationships.- 2.7. Analogy between Polymer Blends and Crystalline Homopolymers.- 2.8. Polymer Blend Chronology.- Appendix A. Counterpart Phase Separation Characteristics of Metallic Alloys and Inorganic Glasses.- Bibliography of Polymer Blend Symposia.- 3. Rubber-Toughened Plastics.- 3.1. Synthesis and Morphology.- 3.1.1. Impact-Resistant Polystyrene.- 3.1.1.1. Solution-Type Graft Copolymers.- 3.1.1.2. Phase Inversion.- 3.1.1.3. Grafting vs. Mechanical Entrapment.- 3.1.2. ABS Resins.- 3.1.2.1. Emulsion Polymerization.- 3.1.2.2. Structure of the Latex Grafts.- 3.1.3. Origin of the Cell Structure.- 3.1.4. Poly(vinyl chloride) Blends.- 3.1.5. Mixed Latex Blends.- 3.2. Physical and Mechanical Behavior of Polyblends.- 3.2.1. The Effect of Compatibility on Transition Behavior.- 3.2.2. Impact Resistance and Deformation.- 3.2.2.1. Impact Behavior.- 3.2.2.2. Tensile and Creep Behavior.- 3.2.2.3. Fatigue Behavior.- 3.2.3. Toughening Mechanisms.- 3.2.3.1. Crazing and Shear Phenomena.- 3.2.3.2. Characteristics of the Rubber.- 3.3. Optical Properties of Polyblends.- 3.4. Oxidation and Weathering of Polyblends.- 4. Diblock and Triblock Copolymers.- 4.1. Synthesis.- 4.1.1. Dilithium Initiators.- 4.1.2. Mechanochemical Methods.- 4.2. Solution Behavior of Block Copolymers.- 4.3. Plastic Compositions.- 4.4. Thermoplastic Elastomers.- 4.5. Long-Range Domain Order.- 4.6. Thermodynamics of Domain Characteristics.- 4.7. Thermodynamic Criteria for Phase Separation.- 4.7.1. Zeroth Approximation.- 4.7.2. Dilute Solution Approach.- 4.7.3. Diffusion Equation Approach.- 4.8. Effect of Solvent Casting on Morphology.- 4.9. Effect of Deformation on Morphology.- 4.10. Mixtures of A-B Blocks with A and B Mechanical Blends.- 4.11. Rheological Behavior of Block Copolymers.- 5. Multiblock Copolymers, Including Ionomers.- 5.1. Segmented Polyurethane Elastomers.- 5.1.1. Modulus and Swelling Behavior.- 5.1.2. Stress-Strain Behavior.- 5.1.3. Stress-Optical Behavior.- 5.1.4. Tensile Strength and Abrasion Resistance.- 5.1.5. Some Generalizations.- 5.2. Carboxylic Rubbers an...

Nanostructured Polymer Blends

Nanostructured Polymer Blends PDF Author: Chandran C. Sarath
Publisher: Elsevier Inc. Chapters
ISBN: 0128090782
Category : Technology & Engineering
Languages : en
Pages : 28

Get Book Here

Book Description
Miscibility and compatibility in polymer blends is a topic of great academic and industrial importance. This is because miscibility and compatibility contribute to morphology, properties, and performance. Miscibility results in one phase; compatibility creates a disperse phase with size and stability determined by interfacial interactions. Miscible polymer properties are averaged similar to a plasticizer polymer, and compatible polymers retain properties of each component, such as toughening or reinforcement. With miscible polymer blends the continuous phase dominates properties; the disperse phase contributes via stress transfer. This chapter revisits the criteria for miscibility or compatibility in polymer blends and the contributors of compatibility compared with miscibility and incompatibility. Development of copolymers and their blending with thermosets and thermoplastics result in complex two-phase morphologies. The dynamics of phase separation observed in polymer blends leading to different morphologies and the criteria for phase separation is explained. A nanometer-dispersed phase requires strong interfacial interactions to stabilize the large interfacial area, and this is favored by rapid spinodal phase separation compared with size diminution by high shear. Nanoblends open up a new arena for polymer blends, and research shows that nanoblends have outstanding optical and mechanical properties.

Polymer Blends Volume 1

Polymer Blends Volume 1 PDF Author: Donald R Paul
Publisher: Elsevier
ISBN: 0323138896
Category : Technology & Engineering
Languages : en
Pages : 520

Get Book Here

Book Description
Polymer Blends, Volume 1 highlights the importance of polymer blends as a major new branch of macromolecular science. Topics range from polymer-polymer compatibility and the statistical thermodynamics of polymer blends to the phase separation behavior of polymer-polymer mixtures, transport phenomena in polymer blends, and mechanical properties of multiphase polymer blends. The optical behavior, solid state transition behavior, and rheology of polymer blends are also discussed. This book is organized into 10 chapters and begins with an overview of polymer blends, with emphasis on terminology and the effect of molecular weight on the thermodynamics of polymer blends as well as phase equilibria and transitions. The discussion then turns to the miscibility of homopolymers and copolymers, in bulk and in solution, from the experimental and theoretical viewpoints. The chapters that follow explore the statistical thermodynamics of polymer blends, paying particular attention to the Flory and lattice fluid theories, along with the phase relationship in polymer mixtures. The interfacial energy, structure, and adhesion between polymers in relation to the properties of polymer blends are considered. The final chapter examines the phenomena of low molecular weight penetrant transport. Currently accepted models for unsteady-state and steady-state permeation of polymeric materials are presented. A discussion of unsteady-state absorption and desorption behavior observed in a variety of polymer blends complements the treatment of permeation behavior. This book is intended to provide academic and industrial research scientists and technologists with a broad background in current principles and practice concerning mixed polymer systems.

The Glass Transition

The Glass Transition PDF Author: E. Donth
Publisher: Springer Science & Business Media
ISBN: 3662043653
Category : Science
Languages : en
Pages : 433

Get Book Here

Book Description
Describes and interrelates the following processes: cooperative alpha processes in a cold liquid, structural relaxation in the glass near Tg, the Johari-Goldstein beta process, the Williams-Götze process in a warm liquid, fast nonactivated cage rattling and boson peak, and ultraslow Fischer modes.

Component Contributions to the Dynamics of Miscible Polymer Blends

Component Contributions to the Dynamics of Miscible Polymer Blends PDF Author: Jeffrey Alan Zawada
Publisher:
ISBN:
Category : Polymers
Languages : en
Pages : 340

Get Book Here

Book Description


Polymer-Polymer Miscibility

Polymer-Polymer Miscibility PDF Author: Olagoke Olabis
Publisher: Elsevier
ISBN: 0323153070
Category : Science
Languages : en
Pages : 383

Get Book Here

Book Description
Polymer–Polymer Miscibility discusses miscibility of polymeric mixtures. This book explains the theoretical and practical aspects of polymer miscibility, which has become a considerable area of research in many academic and industrial laboratories. Comprised of seven chapters, this book starts with an overview of the physical nature of the variations of the basic polymer structure. This monograph then discusses the two cases of miscible polymer blends, namely, poly(vinyl chloride) (PVC)–butadiene/acrylonitrile copolymer (NBR) and polystyrene–poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) blends. This text explores the useful and unique properties of blends of poly(vinyl chloride) and butadiene/acrylonitrile copolymer rubber. Other chapters discuss the thermodynamic theories for the phase separation of block copolymers. The reader is also introduced to other variations of chemical structure, which can result in the permanent attachment of polymers to each other through block and graft copolymers. This text also explores the feasibility of covalent bonding of polymer components. This book is intended for chemical engineers and materials scientists.