Parthiban A. Synthesis and applications of copolymers

New Jersey: Wiley, 2014. — 404 p.Natural polymers such as cellulose and rubber are intertwined with technological advances at various ages of human activity. Also, many technological develop- ments in the space age are centered around the development of polymers. Both light weight and processability have been the key factors that advanced and broadened the use of polymers. The frontiers of technology are constantly pushed forward because of factors such as environmental regulations and depletion of resources, which make development of high performance materials a constant affair.
In the modern era, polymers are widely used in everyday life in a variety of forms such as lms, bers, foams, molded articles, and sheets. Polymers are also used as adhesives, binders, llers and in various other forms. In some of these applications, polymers are used in the dispersed form either in a solid matrix or in a liquid form. It is often the case that polymers that are made up of single monomers do not possess the desired properties in terms of processability, thermomechanical properties and surface compatibility. Polymerization of one monomer with other monomers, com- monly referred to as copolymerization, is one of the strategies often used to improve various properties of polymers such as adhesion, lm-forming tendency, high tem- perature performance, processability, solvent resistance and wettability. Reactivity of monomers becomes crucial in determining the outcome of such polymerization processes. Since the physicochemical characteristics of each monomer are unique, their polymerization nature also varies with the monomer. Hence, it is important to understand the reactivity of monomers and reaction conditions in order to make copolymers, which are completely or predominantly free of homopolymers so that the newly formed polymeric materials exhibit properties expected of them.
Reports on the synthesis and properties of copolymers remain scattered in jour- nal publications and conference proceedings. The focus of some review articles and dedicated conference proceedings also tend to be relatively narrow in scope, revolv- ing around one key area of application. Unlike all previously published articles and materials available in public domain, this book aims to be broad in scope so that it may appeal to a wider section of professionals, from students to research scientists, in academia and industry. By keeping this in mind, a broad range of subjects have been covered.
This book is divided into two sections with the rst section covering synthesis of copolymers and the second section discussing various applications of copoly- mers. One unique characteristic of polymers is their ability to form lms; because of which they nd application in areas as far apart as conducting materials to struc- tural resins. The ability to form thin lms in polymers has been widely exploited in areas such as antifouling surfaces, capacitors, conducting coatings, dielectric materials, lubricants, photosensitive materials, semiconductors and solar cells. The nal application of a polymer is determined by the backbone composition which in turn is decided by the nature of monomers used during polymerization. These monomers differ in functionality and hence the mode of polymerization differs as well. These complexities bring in challenges not only for design and synthe- sis of monomers but also for polymerization of these monomers. As discussed in Chapter 1, synthetic techniques for making polymers are constantly evolving and the trend is more and more toward controlling the chain length, chain-end func- tionality, composition, arrangement of monomer (sequence) in the chain, and so on. Polyole ns are well known for over half a century at present. There have been many interesting developments of materials and mechanisms over the years such as ultrahigh molecular weight (UHMW) polymers and chain shuttling, respectively. However, as described in Chapter 2, some developments like copolymerization with functional monomers are still elusive. Chapter 2 also gives a detailed mechanistic account of ole n polymerization. Polymerization of vinyl monomers constitutes one of the most important, high volume industrial activities. Property tuning by copolymerization is a vital process and the reactivity of monomers is an impor- tant parameter that determines the copolymer formation as well as composition of copolymers. These are the subjects covered as part of Chapter 3. Quite apart from introducing comonomers during polymerization in order to tune the properties of polymers, it is also quite possible to in uence polymer properties by performing post-polymerization reactions. Polymers possessing reactive functional groups that are otherwise inert during polymerization are useful for this purpose. The cyclic carbonate group, with its ability to undergo nucleophilic addition with amines and alcohols, is one such suitable functionality. Synthesis and its speci c properties of such polymers are discussed in detail in Chapter 4. Depletion of fossil fuels as well as efforts to curtail the emission of green house warming gases has increased the focus in the direction of renewable processes and materials. Chapter 5 sum- marizes the state of the art as well as the possibility of making various monomers and polymers by renewable processes. One of the recent developments in polymer synthesis has been forming polymers by reacting monomers bearing multiple func- tional groups. Depending on the symmetry and reactivity of monomers involved, ladder type, networked, and hyper-branched polymers are formed, as described in Chapters 6 and 7. Chapter 6 exhaustively analyzes the synthesis, nature, and type of pores formed and applications of microporous organic polymers. Chapter 7 pro- vides a broad account of various synthetic strategies and type of monomers used for making dendritic copolymers.
Fixing carbon dioxide (CO2), a global warming gas whose emission increased proportionately with various industrial activities of humans, is one of the aims of the global research community. Chapter 8 describes a potential application of copoly- mers obtained by xing CO2 in the area of polymer electrolytes. The key feature of copolymers in particular block copolymers is its ability to self-assemble. The nanopatterns formed as a result of such self-assembly have been proposed in var- ious applications in electronic industry as discussed in Chapter 9. Polymers that exhibit solubility characteristics dependent on external stimuli, such as tempera- ture owing to structural changes that accompany temperature, are useful for many applications such as controlled release of active ingredients and injectable drug delivery. Chapter 10 gives a detailed account of stimuli-responsive polymers, that is, various stimulants and applications of the stimuli-responsive polymers. Histori- cally, many biocompatible and biodegradable polymers have been used as coating materials for drugs. Chapter 11 provides a detailed summary of such pharmaceuti- cal polymers. It is a recent trend in the biomedical eld to covalently link drugs and polymers, commonly called polymer conjugates, in order to either increase the solu- bility of drugs or slow down the rate of absorption of drugs by the human body. Such delayed release not only maintains a desired concentration of drugs in the body but also helps to overcome the toxicity possessed by some drugs. Chapter 12 gives an overview of polymer–drug conjugates and other related up-to-date developments.CONTENTS
SECTION I SYNTHESIS OF COPOLYMERS
Trends in Synthetic Strategies for Making (CO)Polymers
Functional Polyole ns from the Coordination Copolymerization of Vinyl Monomers
General Aspects of Copolymerization
Polymers Bearing Reactive, Pendant Cyclic Carbonate (CC) Group: Syntheses, Post-Polymerization Modi cations, and Applications
Monomers and Polymers Derived from Renewable or Partially Renewable Resources
Microporous Organic Polymers: Synthesis,Types, and Applications
Dendritic Copolymers
SECTION II APPLICATIONS OF COPOLYMERS
A New Class of Ion-Conductive Polymer Electrolytes: CO2/Epoxide Alternating Copolymers With Lithium Salts
Block Copolymer Nanopatterns as Enabling Platforms for Device Applications—Status, Issues, and Challenges
Stimuli-Responsive Copolymers and Their Applications
Pharmaceutical Polymers
Polymer Conjugates of Proteins and Drugs to Improve Therapeutics