Fundamental Concepts in Polymer Science

Before we embark on studying polymer science, we must revisit some fundamental concepts in chemistry and familiarize ourselves with new definitions. 

This section lists fundamental definitions related to polymer science and connects them to the chapters where they appear in this book. Whenever possible, the terms are based on the recommendation of the International Union of Pure and Applied Chemistry (lUPAC), which serves as resource material for the course (Appendix A). 

Active Center or Active Site or Kinetic Chain Carrier (chain polymerization)—site on a chain carrier at which reaction occurs. 

Anabolism—a metabolic process in which complex molecules are synthesized from simpler ones with storage of energy. 

Anionic Polymerization—ionic pol5mierization in which the active centers are anions. 

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Before discussing the detailed chemistry, kinetics, and mechanisms of the various pathways of polymer synthesis, it is necessary to introduce some of the fundamental concepts of polymer science in order to provide essential background to such a development. We need to know what a polymer is and how it is named and classified. It is also necessary to obtain an appreciation of the molecular size and shape of polymer molecules, the molar mass characteristics, the important transition temperatures of polymers, and their distinctive behavior both in solid state and in solution. These concerns are addressed in the first four chapters of the book while the remaining six chapters deal with the important categories of polymerization processes and their mechanisms and kinetic aspects. Throughout this journey the narrative in the text is illuminated with thoughtfully worked out examples which not only complement but also supplement, where necessary, the theoretical development in the text. 

In this introductory chapter the basic information on polymer blends (with a special emphasis on the commercial alloys) is presented in the sequence (i) a historical perspective on the polymer science and technology, (ii) polymeric structures and nomenclature, (iii) fundamental concepts in polymer blend science, and (iv) evolution of polymer blends technology. 

Polymer Science A Comprehensive Reference provides complete and up-to-date coverage of the most important contemporary aspects and fundamental concepts of polymer science. It will become the indispensable reference not only for polymer scientists but also for all researchers in disciplines related to macromolecular systems. 

The words basic concepts" in the title define what I mean by fundamental." This is the primary emphasis in this presentation. Practical applications of polymers are cited frequently—after all, it is these applications that make polymers such an important class of chemicals—but in overall content, the stress is on fundamental principles. Foundational" might be another way to describe this. I have not attempted to cover all aspects of polymer science, but the topics that have been discussed lay the foundstion—built on the bedrock of organic and physical chemistry—from which virtually all aspects of the subject are developed. There is an enormous literature in polymer science this book is intended to bridge the gap between the typical undergraduate background in polymers—which frequently amounts to little more than occasional relevant" examples in other courses—and the professional literature on the subject. 

Some basic concepts and definitions of terms used in the polymer literature are reviewed in this chapter. Much of the terminology in current use in polymer science has technological origins, and some meanings may therefore be understood by convention as well as by definition. Some of these terms are included in this chapter since a full appreciation of the behavior and potential of polymeric materials requires acquaintance with technical developments as well as with the more academic fundamentals of the field. An aim of this book is to provide the reader with the basic understanding and vocabulary for further independent study in both areas. 

Many of the terms, definitions, and concepts used in polymer science are not encountered in other branches of science and must be understood in order to fully discuss the synthesis, characterization, structure, and properties of polymers. While most of these will be discussed in detail in subsequent chapters, some are of such fundamental importance that they must be introduced at the beginning. 

In this brief overview of polymer synthesis, I have tried to introduce some of the main principles that can be used as a foundation for many of the topics discussed in much more detail in subsequent chapters. I have attempted to highlight important issues that are fundamental to polymer synthesis, but many concepts and methods have not been covered. Rest assured that this is not due to some inherent lack of importance or relevance I hope that this chapter will provide some context for the researchers without a background in polymer science but a desire to explore and understand the fascinating topics included in this compendium. 

In addition to the use of polymers to study fundamental concepts in mechanics, another driving force for the critical link between polymer science and mechanics has been use of polymers in applications. As the understanding of the physical nature of polymers increased and synthesis techniques matured, many polymers of widespread usage were developed. As these materials were employed in devices and structures, it was essential to analyze and understand from an engineering perspective the response of polymers to load and other environmental variables, such as temperature and moisture. As indicated earlier, today high performance polymer composites are used for critical load bearing applications as diverse as alpine skis and airframe parts, and thus the study of the mechanics of polymers as a structural material is an active and important area of research. Later sections in this text will deal explicitly with the viscoelastic nature of polymeric response and mathematical methods to analyze this behavior. 

The present book was prepared to provide an introduction to the field of inorganic polymers. There has long been a need for such a book, as opposed to the ready availability of numerous other books, that are highly specialized and written for scientists already working in this area. The only background required for its comprehension are the basic concepts presented in a typical undergraduate course in chemistry. Some famil-iarty with the fundamentals of polymer science would be helpful, but not necessary, since many of these are covered in an introductory chapter on polymer characterization. 

Polymer science dates from the recognition that polymers - such as rubber, cellulose, polystyrene, to name a few - consist of the very large molecules that we call macromolecules. More specifically, they consist of long chains of atoms linked by chemical bonds. The number of atoms in these chains usually runs into the thousands. This rudimentary, but fundamental, conception of the molecular constitution of polymeric substances is the cornerstone of modern polymer science. Without it, a science of polymers could not have been founded and elaborated. [3]... 

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