Degradation of Polymers

The development of polymers as an important class of material was inhibited at the first by the premature failure of these versatile compounds in many applications. The deterioration of important properties of both natural and synthetic polymers is the result of irreversible changes in composition and structure of polymers molecules. As a result of these reactions, mechanical, electrical and/or aesthetic properties are degraded beyond acceptable limits. It is now generally recognized that stabilization against degradation is necessary if the useful life of polymers is to be extended sufficiently to meet design requirements for long-term applications. Polymers degrade by a wide variety of mechanisms, several of which affect all polymers through to varying degree. This monograph will concentrate on those degradation mechanisms which result from reactions of polymers with oxygen in its various forms and which are accelerated by heat and/or radiation. Those stabilization mechanisms are discussed which are based on an understanding of degradation reaction mechanisms that are reasonably well established. The stabilization of polymers is still undergoing a transition from an art to a science as mechanisms of degradation become more fully developed. A scientific approach to stabilization can only be approached when there is an understanding of the reactions that lead to degradation. Stabilization against biodegradation and burning will not be discussed since there is not a clear understanding of how polymers degrade under these conditions.

Bio-degradable polymers are rapidly emerging as a sustainable alternative to traditional petroleum-based plastics and polymers. However, the synthesis and processing of such polymers present unique challenges and opportunities. In this comprehensive volume, Dr. Saha and her team provide an in-depth exploration of the synthesis and processing of bio-degradable polymers and their emerging applications in various sectors from drug delivery to food packaging. Covering a wide range of topics, including synthesis, modification, processing techniques, and few of their advanced applications in emerging areas, this book provides a comprehensive overview of the field. The authors also delve into cutting-edge research on the synthesis, properties and applications of bio-degradable polymers in various fields, such as agricultural, food preservation, biomedical arena, energy storage and other advanced application areas. This volume is an essential resource for scientists, engineers, and policymakers interested in the future of sustainable materials. Whether you are a researcher looking to expand your knowledge of biodegradable polymer synthesis and processing or a policymaker interested in the potential of biodegradable polymers to reduce our reliance on fossil fuels, this book is an invaluable guide to the field.

This book discusses the methods synthesizing various carbon materials, like graphite, carbon blacks, carbon fibers, carbon nanotubes, and graphene. It also details different functionalization and modification processes used to improve the properties of these materials and composites. From a geometrical–structural point of view, it examines different properties of the composites, such as mechanical, electrical, dielectric, thermal, rheological, morphological, spectroscopic, electronic, optical, and toxic, and describes the effects of carbon types and their geometrical structure on the properties and applications of composites.

Few scientific developments in recent years have captured the popular imagination like the subject of'biodegradable' plastics. The reasons for this are complex and lie deep in the human subconscious. Discarded plastics are an intrusion on the sea shore and in the countryside. The fact that nature's litter abounds in the sea and on land is acceptable because it is biodegradable - even though it may take many years to be bioassimilated into the ecosystem. Plastics litter is not seen to be biodegradable and is aesthetically unacceptable because it does not blend into the natural environment. To the environmentally aware but often scientifically naive, biodegradation is seen to be the ecologically acceptable solution to the problem of plastic packaging waste and litter and some packaging manufacturers have exploited the 'green' consumer with exaggerated claims to 'environmentally friendly' biodegradable packaging materials. The principles underlying environmental degradation are not understood even by some manufacturers of 'biodegradable' materials and the claims made for them have been categorized as 'deceptive' by USA legislative authorities. This has set back the acceptance of plastics with controlled biodegradability as part of the overall waste and litter control strategy. At the opposite end of the commercial spectrum, the polymer manufactur ing industries, through their trade associations, have been at pains to discount the role of degradable materials in waste and litter management. This negative campaign has concentrated on the supposed incompatibility of degradable plastics with aspects of waste management strategy, notably materials recycling.

This book presents a multidisciplinary assessment of the state of science in the use of systemic delivery technologies to deliver anti-aging therapeutics now under development. There is a gap between basic aging research and the development of intervention technologies. This major obstacle must be overcome before biogerontological interventions can be put into clinical practice. As biogerontology comes to understand aging as a systemic degenerative process, it is clear that there is a pressing need for technologies that enable cells and tissues in a fully developed adult body to be manipulated systemically to combat aging. The authors review advances in the chemistry and engineering of systemic delivery methods and analyze the strengths and limitations of each. The book is organized into six sections. The first offers an overview of the need for systemic delivery technologies alongside the development of anti-aging therapies and describes approaches that will be required for studying the properties and efficiency of carriers for systemic delivery. Sections II, III and IV describe recent advances in a range of strategies that may enable systemic delivery to help combat aging conditions ranging from cell senescence to decline in immune function and hormonal secretion. Section V discusses practical strategies to engineer and optimize the performance of delivery technologies for applications in systemic delivery, along with their working principles. The final section discusses technical and biological barriers that must be overcome as systemic delivery technologies move from research laboratory to clinical applications aimed at tackling aging and age-associated diseases. Benefiting scholars, students and a broader audience of interested readers, the book includes helpful glossary sections in each chapter, as well as sidebars that highlight important notes, and questions for future research.

Describes harmful elements and their bioremediation techniques for tannery waste, oil spills, wastewater, greenhouse gases, plastic and other wastes. Microenvironmental conditions in soil provide a natural niche for ultra-structures, microbes and microenvironments. The natural biodiversity of these microenvironments is being disturbed by industrialization and the proliferation of urban centers, and synthetic contaminants found in these micro-places are causing stress and instability in the biochemical systems of microbes. The development of new metabolic pathways from intrinsic metabolic cycles facilitate microbial degradation of diverse resistant synthetic compounds present in soil. These are a vital, competent and cost-effective substitute to conventional treatments. Highly developed techniques for bioremediation of these synthetic compounds are increasing and these techniques facilitate the development of a safe environment using renewable biomaterial for removal of toxic heavy metals and xenobiotics. Soil Microenvironment for Bioremediation and Polymer Production consists of 21 chapters by subject matter experts and is divided into four parts: Soil Microenvironment and Biotransformation Mechanisms; Synergistic Effects between Substrates and Microbes; Polyhydroxyalakanoates: Resources, Demands and Sustainability; and Cellulose-Based Biomaterials. This timely and important book highlights Chapters on classical bioremediation approaches and advances in the use of nanoparticles for removal of radioactive waste Discusses the production of applied emerging biopolymers using diverse microorganisms Provides the most innovative practices in the field of bioremediation Explores new techniques that will help to improve biopolymer production from bacteria Provides novel concepts for the most affordable and economic societal benefits.

This new volume, Natural Polymers: Perspectives and Applications for a Green Approach, covers the synthesis, characterizations, and properties of natural polymeric systems, including their morphology, structure, and dynamics. It also introduces the most recent innovations and applications of natural polymers and their composites in the food, construction, electronics, biomedical, pharmaceutical, and engineering industries. Natural polymers provide a striking substitute for various applications as compared to synthetic polymers obtained from petrochemicals because they are biocompatible, biodegradable, easily available, and fall within the budget of many industries. The applications of natural polymers in pharmaceutical industries are large in comparison to synthetic polymers and are also wide in scope in the food and cosmetic industries. This new volume provides the information needed to design new applications for natural polymers. This book is a valuable reference for researchers, academicians, chemists, pharmacists, researchers, scientists, industrialists dealing with applications of natural polymers and people working in field of natural polymers.

The revised edition of the renowned and bestselling title is the most comprehensive single text on all aspects of biomaterials science from principles to applications. Biomaterials Science, fourth edition, provides a balanced, insightful approach to both the learning of the science and technology of biomaterials and acts as the key reference for practitioners who are involved in the applications of materials in medicine.This new edition incorporates key updates to reflect the latest relevant research in the field, particularly in the applications section, which includes the latest in topics such as nanotechnology, robotic implantation, and biomaterials utilized in cancer research detection and therapy. Other additions include regenerative engineering, 3D printing, personalized medicine and organs on a chip. Translation from the lab to commercial products is emphasized with new content dedicated to medical device development, global issues related to translation, and issues of quality assurance and reimbursement. In response to customer feedback, the new edition also features consolidation of redundant material to ensure clarity and focus. Biomaterials Science, 4th edition is an important update to the best-selling text, vital to the biomaterials’ community. The most comprehensive coverage of principles and applications of all classes of biomaterials Edited and contributed by the best-known figures in the biomaterials field today; fully endorsed and supported by the Society for Biomaterials Fully revised and updated to address issues of translation, nanotechnology, additive manufacturing, organs on chip, precision medicine and much more. Online chapter exercises available for most chapters