Kinetic modeling of the polypropylene photothermal oxidation PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Kinetic modeling of the polypropylene photothermal oxidation PDF full book. Access full book title Kinetic modeling of the polypropylene photothermal oxidation by Alexandre Francois heude. Download full books in PDF and EPUB format.
Author: Alexandre Francois heude
Publisher:
ISBN:
Category :
Languages : fr
Pages : 0
Get Book Here
Book Description
Le développement d'outils numériques de prédiction de la durée de vie des polymères constitue un levier prometteur pour réduire les durées des processus de certification de ces matériaux dans le domaine automobile sans sacrifier leur fiabilité. Cette thèse s'applique à la modélisation de la photo-thermo-oxydation du polypropylène isotactique (iPP), laquelle est responsable de l'altération de ses propriétés mécaniques et d'aspect. L'approche adoptée consiste à coupler la cinétique des réactions de photo- et thermo-oxydation avec des phénomènes physiques, comme le transport du dioxygène et l'atténuation de la lumière UV dans l'épaisseur du matériau, pour décrire l'ensemble des évolutions physico-chimiques. Les propriétés aux échelles supérieures, sur lesquelles seront définis les critères de fin de vie, seront calculées a posteriori en appliquant les relations structure-propriété adéquates. Le principal enjeu était d'étendre le modèle cinétique de vieillissement thermique préexistant au vieillissement photo-thermique en prenant en compte les réactions d'amorçage photolytique. De lourdes campagnes d'essais de vieillissement et de caractérisation menées sur un iPP de référence, ainsi qu'une capitalisation exhaustive des données de la littérature d'autres iPPs, ont permis de mettre au point un modèle cinétique de photo-thermo-oxydation et de le généraliser à l'ensemble de la famille des iPPs dans de larges domaines de pression partielle d'oxygène (de 0.2 à 50 bars), de température (de 40 à 230°C) et d'exposition à la lumière UV (intensités et sources lumineuses variables) décrivant des conditions de vieillissements naturels et accélérés. La validation expérimentale du modèle a permis d'étayer l'approche cinétique et de montrer ses limites, mais aussi de révéler un certain nombre d'enjeux numériques. Le modèle a été conçu pour être un outil numérique évolutif qui permettra, à terme, d'optimiser la représentativité des méthodes d'essais de vieillissement et la performance des formulations commerciales d'iPP. L'ensemble de ces développements théoriques et numériques peut être appliqué à la photo-thermo-dégradation d'autres types de polymères, mais aussi dans d'autres champs d'application de la photochimie macromoléculaire telle que la photo-polymérisation UV.Mots-Clés : Polypropylène, photo-thermo-oxydation, contrôle par la diffusion d'oxygène, effet d'écran, modélisation cinétique, prédiction de durée de vie.
Author: Alexandre Francois heude
Publisher:
ISBN:
Category :
Languages : fr
Pages : 0
Get Book Here
Book Description
Le développement d'outils numériques de prédiction de la durée de vie des polymères constitue un levier prometteur pour réduire les durées des processus de certification de ces matériaux dans le domaine automobile sans sacrifier leur fiabilité. Cette thèse s'applique à la modélisation de la photo-thermo-oxydation du polypropylène isotactique (iPP), laquelle est responsable de l'altération de ses propriétés mécaniques et d'aspect. L'approche adoptée consiste à coupler la cinétique des réactions de photo- et thermo-oxydation avec des phénomènes physiques, comme le transport du dioxygène et l'atténuation de la lumière UV dans l'épaisseur du matériau, pour décrire l'ensemble des évolutions physico-chimiques. Les propriétés aux échelles supérieures, sur lesquelles seront définis les critères de fin de vie, seront calculées a posteriori en appliquant les relations structure-propriété adéquates. Le principal enjeu était d'étendre le modèle cinétique de vieillissement thermique préexistant au vieillissement photo-thermique en prenant en compte les réactions d'amorçage photolytique. De lourdes campagnes d'essais de vieillissement et de caractérisation menées sur un iPP de référence, ainsi qu'une capitalisation exhaustive des données de la littérature d'autres iPPs, ont permis de mettre au point un modèle cinétique de photo-thermo-oxydation et de le généraliser à l'ensemble de la famille des iPPs dans de larges domaines de pression partielle d'oxygène (de 0.2 à 50 bars), de température (de 40 à 230°C) et d'exposition à la lumière UV (intensités et sources lumineuses variables) décrivant des conditions de vieillissements naturels et accélérés. La validation expérimentale du modèle a permis d'étayer l'approche cinétique et de montrer ses limites, mais aussi de révéler un certain nombre d'enjeux numériques. Le modèle a été conçu pour être un outil numérique évolutif qui permettra, à terme, d'optimiser la représentativité des méthodes d'essais de vieillissement et la performance des formulations commerciales d'iPP. L'ensemble de ces développements théoriques et numériques peut être appliqué à la photo-thermo-dégradation d'autres types de polymères, mais aussi dans d'autres champs d'application de la photochimie macromoléculaire telle que la photo-polymérisation UV.Mots-Clés : Polypropylène, photo-thermo-oxydation, contrôle par la diffusion d'oxygène, effet d'écran, modélisation cinétique, prédiction de durée de vie.
Author:
Publisher: Elsevier
ISBN: 0081028660
Category : Science
Languages : en
Pages : 4871
Get Book Here
Book Description
Materials in a nuclear environment are exposed to extreme conditions of radiation, temperature and/or corrosion, and in many cases the combination of these makes the material behavior very different from conventional materials. This is evident for the four major technological challenges the nuclear technology domain is facing currently: (i) long-term operation of existing Generation II nuclear power plants, (ii) the design of the next generation reactors (Generation IV), (iii) the construction of the ITER fusion reactor in Cadarache (France), (iv) and the intermediate and final disposal of nuclear waste. In order to address these challenges, engineers and designers need to know the properties of a wide variety of materials under these conditions and to understand the underlying processes affecting changes in their behavior, in order to assess their performance and to determine the limits of operation. Comprehensive Nuclear Materials, Second Edition, Seven Volume Set provides broad ranging, validated summaries of all the major topics in the field of nuclear material research for fission as well as fusion reactor systems. Attention is given to the fundamental scientific aspects of nuclear materials: fuel and structural materials for fission reactors, waste materials, and materials for fusion reactors. The articles are written at a level that allows undergraduate students to understand the material, while providing active researchers with a ready reference resource of information. Most of the chapters from the first Edition have been revised and updated and a significant number of new topics are covered in completely new material. During the ten years between the two editions, the challenge for applications of nuclear materials has been significantly impacted by world events, public awareness, and technological innovation. Materials play a key role as enablers of new technologies, and we trust that this new edition of Comprehensive Nuclear Materials has captured the key recent developments. Critically reviews the major classes and functions of materials, supporting the selection, assessment, validation and engineering of materials in extreme nuclear environments Comprehensive resource for up-to-date and authoritative information which is not always available elsewhere, even in journals Provides an in-depth treatment of materials modeling and simulation, with a specific focus on nuclear issues Serves as an excellent entry point for students and researchers new to the field
Author: Sabu Thomas
Publisher: Elsevier
ISBN: 0128163038
Category : Technology & Engineering
Languages : en
Pages : 658
Get Book Here
Book Description
Unsaturated Polyester Resins: Fundamentals, Design, Fabrication, and Applications explains the preparation, techniques and applications relating to the use of unsaturated polyester resin systems for blends, interpenetrating polymer networks (IPNs), gels, composites and nanocomposites, enabling readers to understand and utilize the improved material properties that UPRs facilitate. Chapters cover unsaturated polyester resins and their interaction at the macro, micro and nano levels, in-depth studies on the properties and analysis of UPR based materials, and the applications of UPR based composites, blends, IPNs and gels across a range of advanced commercial and industrial fields. This is a highly detailed source of information on unsaturated polyester resins, supporting academics, researchers and postgraduate students working with UPRs, polyesters, polymeric or composite materials, polymer chemistry, polymer physics, and materials science, as well as scientists, R&D professionals and engineers in industry. - Covers the use of unsaturated polyester resin systems for blends, IPNs, gels, composites and nanocomposites - Presents cutting-edge techniques for the analysis and improvement of properties of advanced UPR-based materials - Unlocks the potential of unsaturated polyester resins in high-performance materials for a range of advanced applications
Author: Anthony L. Andrady
Publisher: John Wiley & Sons
ISBN: 1119768403
Category : Technology & Engineering
Languages : en
Pages : 516
Get Book Here
Book Description
An insightful and multidisciplinary exploration of plastic pollutants in the ocean environment In Plastics and the Ocean, renowned researcher Anthony L. Andrady delivers a comprehensive and up-to-date treatment of the sources, characterization, and environmental impacts of plastics in the ocean. The book focuses on macroplastics as well as micro-scale and nanoscale plastics and the human impacts of these that reach consumers via seafood. It also addresses the human behavioral aspects of the problem via discussions of the mismanagement of urban litter. A diverse collection of expert perspectives is arranged logically and guides the reader through this fast-evolving multi-disciplinary subject area. Beginning with an overview of the field, the book goes on to explore the importance of this area of research to related disciplines and to the everyday lives of consumers. This text offers engineers and scientists an up-to-date review of the subject and the state of the art as summarized by key researchers in the field. The book includes: A synthesis of leading voices in oceanography, biogeochemistry, industrial chemistry, ecotoxicology, polymer science, and behavioral science Discussions of the impacts of a range of marine plastics, including large debris, microplastics, and nanoplastics A summary of the abundance and impacts of plastics in various niches in the marine environment Descriptions of the current methodologies for sampling, detection, processing, and identification of plastic waste Plastics and the Ocean is an indispensable resource for professionals, researchers, instructors, and graduate students in polymer science, marine biology, and environmental engineering. It’s also a must-read text for chemical engineers, materials scientists, and environmental engineers seeking a one-stop resource that describes the origins, occurrence, composition, environmental fate, and biological impacts of plastic pollutants in an ocean environment.
Author: A. R. Bunsell
Publisher: Woodhead Publishing
ISBN: 008101886X
Category : Technology & Engineering
Languages : en
Pages : 1054
Get Book Here
Book Description
Handbook of Properties of Textile and Technical Fibres, Second Edition introduces tensile properties and failure and testing of fibers, also examining tensile properties and the failure of natural fibers, such as cotton, hemp, flax, agave, wool and silk. Next, the book discusses the tensile properties and failure of synthetic fibers, ranging from polyamide, polyester, polyethylene and carbon fibers. Chapters provide a general background of the fiber, including its manufacture, microstructure, factors that affect tensile properties and methods to improve tensile failure. With its distinguished editor and international contributors, this book is an important reference for fiber scientists, textile technologists, engineers and academics. - Offers up-to-date coverage of new and advanced materials for the fiber and textile industries - Reviews structure-property relationships of high-performance natural, synthetic polymer and inorganic fibers - Offers a range of perspectives on the tensile properties of fibers from an international team of authors with diverse expertise in academic research and in textile development and manufacture
Author: George Wypych
Publisher: Elsevier
ISBN: 1927885582
Category : Technology & Engineering
Languages : en
Pages : 519
Get Book Here
Book Description
Handbook of UV Degradation and Stabilization, Third Edition, discusses different aspects of UV-related phenomena that occur when polymeric materials are exposed to UV radiation. It reviews existing literature, looking at how plants, animals and humans protect themselves against UV radiation. This review permits evaluation of mechanisms of protection against UV used by living things and potential application of these mechanisms in the protection of natural and synthetic polymeric materials. Other chapters look at more specific aspects of UV degradation and stabilization, such as specific polymers and rubbers, analytical methods used in UV stabilization, health and safety, and more. This book is an excellent companion to the Databook of UV stabilizers which has also been published recently. Both books supplement each other without repeating the same information – one contains data another theory, mechanisms of action, practical effects and implications of application. - Provides a practical reference guide for engineers and scientists who design with plastics and formulate plastic materials - Explains the effect of UV light on plastics and how to mitigate its effects through the use of UV stabilizers - Surveys the range of UV stabilizers on the market and provides advice on their selection and use
Author: Melanie Bergmann
Publisher: Springer
ISBN: 3319165100
Category : Science
Languages : en
Pages : 456
Get Book Here
Book Description
This book describes how man-made litter, primarily plastic, has spread into the remotest parts of the oceans and covers all aspects of this pollution problem from the impacts on wildlife and human health to socio-economic and political issues. Marine litter is a prime threat to marine wildlife, habitats and food webs worldwide. The book illustrates how advanced technologies from deep-sea research, microbiology and mathematic modelling as well as classic beach litter counts by volunteers contributed to the broad awareness of marine litter as a problem of global significance. The authors summarise more than five decades of marine litter research, which receives growing attention after the recent discovery of great oceanic garbage patches and the ubiquity of microscopic plastic particles in marine organisms and habitats. In 16 chapters, authors from all over the world have created a universal view on the diverse field of marine litter pollution, the biological impacts, dedicated research activities, and the various national and international legislative efforts to combat this environmental problem. They recommend future research directions necessary for a comprehensive understanding of this environmental issue and the development of efficient management strategies. This book addresses scientists, and it provides a solid knowledge base for policy makers, NGOs, and the broader public.
Author: S C O Ugbolue
Publisher: Woodhead Publishing
ISBN: 0081012519
Category : Technology & Engineering
Languages : en
Pages : 591
Get Book Here
Book Description
Polyolefin Fibres: Structure, Properties and Industrial Applications, Second Edition, explores one of the most widely used commercial polymers, with a focus on the most important polyolefins, namely polyethylene, polypropylene, and polyolefin bicomponent fibres. These versatile fibres are durable, chemically resistant, lightweight, economical, and functional. This new edition has been updated and expanded to include cutting-edge research on a broad range of advanced applications. Part I covers the structure and properties of polyolefin fibres, incorporating a new chapter on the environmental aspects of polyolefin use. Part II examines the methods for improving the functionality of polyolefins, providing essential information for those engaged in developing high-performance materials. A final group of chapters addresses how polyolefin fibres can be incorporated into specific textile applications, such as automotive, geotextile, biomedical, and hygiene products, and explores potential future development. This book is an essential reference for textile technologists and manufacturers, polymer and fibre scientists, yarn and fabric manufacturers, biomedical and device engineers, and industrialists and researchers. - Introduces the types, properties and structure of polyolefin fibers for readers new to the polyolefins field - Examines methods to improve the functionality of polyolefin fibers, providing essential information for textile technologists and research and development managers engaged in developing high-performance materials - Presents existing and potential applications of polyolefin fibers, exploring how they can expand the range of commercial polyolefin-based products
Author: Dina Hamad
Publisher:
ISBN:
Category : Electronic books
Languages : en
Pages : 0
Get Book Here
Book Description
Synthetic water-soluble polymers, well-known refractory pollutants, are abundant in wastewater effluents since they are extensively used in industry in a wide range of applications. These polymers can be effectively degraded by advanced oxidation processes (AOPs). This entry thoroughly covers the development of the photochemical kinetic model of the polyvinyl alcohol (PVA) degradation in UV/H2O2 advanced oxidation batch process that describes the disintegration of the polymer chains in which the statistical moment approach is considered. The reaction mechanism used to describe the photo-degradation of polymers comprises photolysis, polymer chain scission, and mineralization reactions. The impact of operating conditions on the process performance is evaluated. Characterization of the polymer average molecular weights, total organic carbon, and hydrogen peroxide concentrations as essential factors in developing a reliable photochemical model of the UV/H2O2 process is discussed. The statistical moment approach is applied to model the molar population balance of live and dead polymer chains taking into account the probabilistic chain scissions of the polymer. The photochemical kinetic model provides a comprehensive understanding of the impact of the design and operational variables.
Author: Paul Goggin Kelleher
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
