Download or read book Molecular Mechanics of Glassy and Semicrystalline Polymers written by Masoud Razavi and published by . This book was released on 2020 with total page 269 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymers are a unique class of modern materials. Despite their light mass density, their mechanical properties are strong enough for a variety of applications either through crystallization or vitrification to achieve sufficient rigidity. However, high Young's modulus is not the only necessary characteristic. Desirably, polymeric materials should be ductile, for example, tolerating considerable bending. In this regard polymers (at room temperature) can be classified as brittle or ductile polymers. A ductile or brittle polymer structurally, can be either amorphous or semicrystalline. Moreover, a polymeric material (either glassy or semicrystalline) could remain ductile at temperatures much lower than its glass transition temperature (Tg). Ductile polymers include semicrystalline polymers such as polyethylene (PE) and polypropylene (PP) with low Tg, and polyamide with high Tg, as well as some amorphous glassy polymers such as bisphenol A polycarbonate (bpA-PC) and polyethylene terephthalate (PET). Examples of the brittle polymers under ambient conditions, are semicrystalline polymers with high Tg such as semicrystalline PET or Poly(lactic acid) (PLA), or glassy amorphous polymers such as polystyrene (PS) and poly(methyl methacrylate) (PMMA). For decades mechanical behavior of polymers is an important research topic in polymer science and despite the tremendous researches in this filed, there is no comprehensive molecular picture that can universally describe the mechanical behavior of polymeric materials at the molecular level. Consequently, previous studies are not able to propose a method to efficiently improve the mechanical properties of polymers without additives, e.g. turning a brittle polymer to a ductile one.This dissertation consists of two parts: PART A is about the molecular mechanics of glassy amorphous polymers, and PART B focuses on the molecular mechanics of semicrystalline polymers. In each part, we carried out three independent projects to address several important questions in the mechanics of polymer glasses and semicrystalline polymers. Influenced by our recent phenomenological molecular model, this work comprehensively emphasizes on the important role of the chain networking, arising from intra-chain connectivity and chain uncrossability, on affording ductility into the polymeric materials.Chapter I is a general introduction into the PART A. In Chapter II we study several different polymer glasses in tensile, creep and stress relaxation mechanical experiments in order to understand the crazing behavior of polymer glasses. Based on our inclusive experiments and counterintuitive results, an alternative molecular mechanism and model is proposed to explain craze initiation in polymer glasses. This chapter also includes a refrainment to our recent phenomenological molecular model. Chapter III studies the two-phase rubber-toughened polymer glasses. It is indicated that the commercial rubber-toughened polymer glasses do not undergo molecular level yielding characterized by the increased segmental mobility, thus we title the strain softening point of these materials as apparent yield point. Methods to switch the mechanism of yielding from apparent to the real one is also proposed. A novel rubber-toughening mechanism that is operative in the recently synthesized nano-rubber-toughened PMMA by Dow chemicals, is suggested. In Chapter IV, real-time birefringence measurements during different mechanical experiments of PMMA and PS is performed in order to achieve molecular level insights into the deformation of polymer glasses. For the first time, birefringence changes at the post-yield deformation of PS and PMMA are measured. Attempts are made to explain the molecular reasons of the birefringence changes and its correlation/decorrelation with stress, during different mechanical experiments including uniaxial tensile, creep and stress relaxation experiments.By an analogy with PART A, PART B of dissertation, starts with a general introduction into the molecular mechanics of semicrystalline polymers in Chapter V. In Chapter VI, our general framework and universal molecular picture of the deformation of semicrystalline polymers are introduced. Chapter VII investigates the molecular mechanics of semicrystalline PLA which is an ideal model semicrystalline polymer, through a comparative study with the mechanics of its amorphous state. Reasons behind mechanical weakness of this polymer and in general any other semicrystalline polymer below Tg, and lower drawability above Tg, are explained in light of the results from time-resolved polarized optical microscope (POM) observations during large deformation of semicrystalline PLA. After identifying the origins of the brittle response of semicrystalline polymers, a universal strategy is proposed in Chapter VIII to turn brittle semicrystalline polymers to ductile. Finally, Chapter IX summarizes the overall body of the dissertation and offers main conclusions.
Download or read book Molecular Mobility in Deforming Polymer Glasses written by Nikhil Padhye and published by Springer Nature. This book was released on 2021-10-15 with total page 111 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book bridges disparate fields in an exploration of the phenomena and applications surrounding molecular mobility in glassy materials experiencing inelastic deformation. The subjects of plastic deformation and polymer motion/interdiffusion currently belong to the two different fields of continuum mechanics and polymer physics, respectively. However, molecular motion associated with plastic deformation is a key ingredient to gain fundamental understanding, both at the macroscopic and microscopic level. This short monograph provides necessary background in the aforementioned fields before addressing the topic of molecular mobility accompanied by macroscopic inelastic deformation in an accessible and easy-to-understand manner. A new phenomenon of solid-state deformation-induced bonding in polymers is discussed in detail, along with some broad implications in several manufacturing sectors. Open questions pertaining to mechanisms, mechanics, and modeling of deformation-induced bonding in polymers are presented. The book’s clear language and careful explanations will speak to readers of diverse backgrounds.
Download or read book The Physics of Glassy Polymers written by R.N. Haward and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 513 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the publication of the first edition of The Physics of Glassy Polymers there have been substantial developments in both the theory and application of polymer physics, and many new materials have been introduced. Furthermore, in this large and growing field of knowledge, glassy polymers are of particular interest because of their homogeneous structure, which is fundamentally simpler than that of crystalline or reinforced materials. This new edition covers all these developments, including the emergence of the polymer molecule with its multiplicity of structure and conformations as the major factor controlling the properties of glassy polymers, using the combined knowledge of a distinguished team of contributors. With an introductory chapter covering the established science in the subject are and summarising concepts assumed in the later chapters, this fully revised and updated second edition is an essential work of reference for those involved in the field.
Download or read book Molecular Dynamics Simulation of the Glass Transition and the Deformation Behavior of Amorphous Polymers written by Yang-Lioe and published by . This book was released on 1997 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Physics of Deformation and Fracture of Polymers written by A. S. Argon and published by Cambridge University Press. This book was released on 2013-03-07 with total page 535 pages. Available in PDF, EPUB and Kindle. Book excerpt: A physical, mechanism-based presentation of the plasticity and fracture of polymers, covering industrial scale applications through to nanoscale biofluidic devices.
Download or read book Molecular Dynamics of Glass Forming Systems written by George Floudas and published by Springer. This book was released on 2013-01-27 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pressure is one of the essential thermodynamic variables that, due to some former experimental difficulties, was long known as the “forgotten variable.” But this has changed over the last decade. This book includes the most essential first experiments from the 1960s and reviews the progress made in understanding glass formation with the application of pressure in the last ten years. The systems include amorphous polymers and glass-forming liquids, polypeptides and polymers blends. The thermodynamics of these systems, the relation of the structural relaxation to the chemical specificity, and their present and future potential applications are discussed in detail. The book provides (a) an overview of systems exhibiting glassy behavior in relation to their molecular structure and provides readers with the current state of knowledge on the liquid-to-glass transformation, (b) emphasizes the relation between thermodynamic state and dynamic response and (c) shows that the information on the pressure effects on dynamics can be employed in the design of materials for particular applications. It is meant to serve as an advanced introductory book for scientists and graduate students working or planning to work with dynamics. Several scientific papers dealing with the effects of pressure on dynamics have appeared in leading journals in the fields of physics in the last ten years. The book provides researchers and students new to the field with an overview of the knowledge that has been gained in a coherent and comprehensive way.
Download or read book Physics and Mechanics of Amorphous Polymers written by Jo Perez and published by Routledge. This book was released on 2018-04-27 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: Topics covered in this text include: structural aspects of polymers; molecular mobility in amorphous solid polymers; non-elastic deformation of solid amorphous polymers; mechanical experiments; interpretation of results; physical ageing of amorphous polymers; and glass transition.
Download or read book Polymer Materials written by Jean Louis Halary and published by John Wiley & Sons. This book was released on 2011-04-04 with total page 743 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced reviews for Polymer Materials "Molecular modeling of polymers ... is a subject that cannot be found in any other [book] in any appreciable detail. ... [T]he detailed chapters on specific polymer systems is a great idea." — Gregory Odegard, Michigan Technological University "The polymer community needs a text book which can connect the macroscopic mechanics with mesoscopic and molecular aspects of polymer." — Liangbin Li, University of Science and Technology of China This book takes a unique, multi-scale approach to the mechanical properties of polymers, covering both the macroscopic and molecular levels unlike any other book on the market. Based on the authors’ extensive research and writing in the field, Polymer Materials emphasizes the relationships between the chemical structure and the mechanical behavior of polymer materials, providing authoritative guidelines for assessing polymer performance under different conditions and the design of new materials. Key features of this book include: Experimental results on selected examples precede and reinforce the development of theoretical features In-depth discussions of a limited number of polymer systems instead of a brief overview of many Self-contained chapters with a summary of their key points Comprehensive problems and a solutions manual for the different parts of the book Coverage of the basics with an emphasis on polymer dynamics An indispensable resource for polymer scientists and students alike, Polymer Materials is also highly useful for material scientists, engineers, chemists, and physicists in industry and academia.
Download or read book Structure and Properties of Glassy Polymers written by Martin R. Tant and published by . This book was released on 1998 with total page 486 pages. Available in PDF, EPUB and Kindle. Book excerpt: In twenty-nine chapters by leading authorities, Structure and Properties of Glassy Polymers provides readers with comprehensive coverage of basic and applied research on glass polymers as well as a wealth of information on current topics such as molecular modeling, characterization, polymer glasses in confined spaces, and conducting glass polymers. The characterization techniques presented include temperature-modulated differential scanning calorimetry, dielectric loss spectroscopy, photochemical hole burning, positron annihilation lifetime spectroscopy, and transient current generation.
Download or read book Polymer Physics written by Wenbing Hu and published by Springer Science & Business Media. This book was released on 2012-11-05 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: A molecular view on the fundamental issues in polymer physics is provided with an aim at students in chemistry, chemical engineering, condensed matter physics and material science courses. An updated translation by the author, a renowned Chinese chemist, it has been proven to be an effective source of learning for many years. Up-to-date developments are reflected throughout the work in this concise presentation of the topic. The author aims at presenting the subject in an efficient manner, which makes this particularly suitable for teaching polymer physics in settings where time is limited, without having to sacrifice the extensive scope that this topic demands.
Download or read book Molecular Modeling of Polymers written by Gregory C. Rutledge and published by John Wiley & Sons. This book was released on 1998 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook of Polymer Synthesis Characterization and Processing written by Enrique Saldivar-Guerra and published by John Wiley & Sons. This book was released on 2013-03-04 with total page 660 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covering a broad range of polymer science topics, Handbook of Polymer Synthesis, Characterization, and Processing provides polymer industry professionals and researchers in polymer science and technology with a single, comprehensive handbook summarizing all aspects involved in the polymer production chain. The handbook focuses on industrially important polymers, analytical techniques, and formulation methods, with chapters covering step-growth, radical, and co-polymerization, crosslinking and grafting, reaction engineering, advanced technology applications, including conjugated, dendritic, and nanomaterial polymers and emulsions, and characterization methods, including spectroscopy, light scattering, and microscopy.
Download or read book Molecular Characterization of Polymers written by Muhammad Imran Malik and published by Elsevier. This book was released on 2021-03-09 with total page 670 pages. Available in PDF, EPUB and Kindle. Book excerpt: Molecular Characterization of Polymers presents a range of advanced and cutting-edge methods for the characterization of polymers at the molecular level, guiding the reader through theory, fundamentals, instrumentation, and applications, and supporting the end goal of efficient material selection and improved material performance. Each chapter focuses on a specific technique or family of techniques, including the different areas of chromatography, field flow fractionation, long chain branching, static and dynamic light scattering, mass spectrometry, NMR, X-Ray and neutron scattering, polymer dilute solution viscometry, microscopy, and vibrational spectroscopy. In each case, in-depth coverage explains how to successfully implement and utilize the technique. This practical resource is highly valuable to researchers and advanced students in polymer science, materials science, and engineering, and to those from other disciplines and industries who are unfamiliar with polymer characterization techniques. Introduces a range of advanced characterization methods, covering aspects such as molecular weight, polydispersity, branching, composition, and tacticity Enables the reader to understand and to compare the available technique, and implement the selected technique(s), with a view to improving properties of the polymeric material Establishes a strong link between basic principles, characterization techniques, and real-life applications
Download or read book Plastics written by Nigel Mills and published by Butterworth-Heinemann. This book was released on 2020-02-16 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plastics: Microstructure and Applications is a key text for senior students studying the science and engineering of plastics materials (or polymers) and will serve as a valuable introduction to the fundamentals of polymer properties for those new to the field. Starting from microstructure and physical properties, the book covers the mechanical, chemical, transport and electrical properties of plastics materials and also deals in detail with wider issues that today’s engineers and materials scientists need, such as manufacturing processes and the design of plastics products. A thorough revision of the book for this 4th edition reflects advances in the field by including more detailed discussion of characterization techniques, crystallization and molecular structure, thermoplastic composites, 3D printing and electrical properties of plastics. The chapter on materials and shape selection covers sustainability, life cycle analysis and waste disposal considerations for plastics materials. Provides introductory information for students of plastics technology, materials science and engineering, mechanical engineering and other fields. A useful introduction to the fundamentals of plastics for academic and industrial researchers from other fields. Includes substantial new coverage of microstructure and morphology of polymers; electrical properties of plastics; modern additive manufacturing and consideration of sustainability and life cycle analysis of plastic materials.
Download or read book Nonlinear Polymer Rheology written by Shi-Qing Wang and published by John Wiley & Sons. This book was released on 2018-02-06 with total page 470 pages. Available in PDF, EPUB and Kindle. Book excerpt: Integrating latest research results and characterization techniques, this book helps readers understand and apply fundamental principles in nonlinear polymer rheology. The author connects the basic theoretical framework with practical polymer processing, which aids practicing scientists and engineers to go beyond the existing knowledge and explore new applications. Although it is not written as a textbook, the content can be used in an upper undergraduate and first year graduate course on polymer rheology. • Describes the emerging phenomena and associated conceptual understanding in the field of nonlinear polymer rheology • Incorporates details on latest experimental discoveries and provides new methodology for research in polymer rheology • Integrates latest research results and new characterization techniques like particle tracking velocimetric method • Focuses on the issues concerning the conceptual and phenomenological foundations for polymer rheology • Has a companion website for readers to access with videos complementing the content within several chapters
Download or read book Relaxation in Physical and Mechanical Behavior of Polymers written by Maxim Arzhakov and published by CRC Press. This book was released on 2019-01-30 with total page 183 pages. Available in PDF, EPUB and Kindle. Book excerpt: Explores the nature of relaxation phenomena in polymers on the basis of time-temperature equivalence. Its role in the physical and mechanical behavior of polymers materials and fundamentals of thermoplastics processing are discussed. Four appendixes detail thermo-mechanical methods to study relaxation in polymers, structure of both amorphous and semi-crystalline polymers, and unified approach to describe deformation of polymeric materials.
Download or read book Molecular Dynamics Simulation of Uni and Bi modal Semicrystalline Polymers written by Zengqiang Zhai and published by . This book was released on 2019 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: Semicrystalline polymers (such as polyethylene, polylactic acid, polyamide, etc.) are used in a wide range of application (such as automotive, pipes, gearing, etc.) due to promoted mechanical properties. There is strong link between the mechanical properties and microstructure of semicrystalline polymer, such as bimodality, molecular topology (the way polymer chains pass through crystalline and amorphous phases), chain entanglements, lamellar thickness, temperature, and so on. However, these microstructure cannot be access quantitatively in experiment. There exists some molecular dynamics investigations, but the homogeneous crystallization is very difficult to achieve and not extensively discussed. Thus, the crystallization mechanism of polymers and the dependence of microstructure remain relatively unclear and controversy. In this thesis, we have performed the homogeneous crystallization of polymers using a coarse-grained molecular dynamics (CG-MD) model published in our previous article 1, which favors chain alignment and crystallization. The main objective of this thesis is to use CG-MD simulation technique to provide more insights of the homogeneous nucleation and crystal growth behavior of bimodal and unimodal MWD polymers, the influence of bimodality on the molecular topology (loop, tie, cilia) and entanglement concentration, the chain disentanglement process and its influence on lamellar thickening as well the temperature dependence.
