[PDF] Block And Graft Copolymers eBook

Author : Gunther Molau
Publisher : Springer Science & Business Media
Page : 326 pages
File Size : 39,80 MB
Release : 2012-12-06
Category : Technology & Engineering
ISBN : 1468419080

GET BOOK

The molecules of block and graft copolymers are molecules of a higher order; they consist of homopolymer subchains which are interconnected by chemical valence bonds. This structural com plexity is manifested in the unusual behavior of block and graft copolymers both in solution and in bulk. Many types of interac tions are possible in block and graft copolymers in the solid state. Polymer subchains of one molecule can interact with other polymer subchains which may belong to the same molecule or to different molecules. Since polymer chains of chemically different composition are usually incompatible, thermodynamically unfavorable as well as thermodynamically favorable interactions exist in the solid state. In solutions of block and graft copolymers, the sit uation becomes even more complex, because interactions between the solvent molecules and the various subchains of the copolymer mole cules occur in addition to the interactions between the polymer chains. This multitude of interactions gives rise to a wide spec trum of colloidal and morphological properties which have no paral lel in less complex polymer systems such as homopolymers or random copolymers. Research on the colloidal and morphological behavior of block and graft copolymers is a relatively new field of endeavor. It started in 1954, when F. M. Merrett fractionated mixtures of grafted na tural rubber with the corresponding homopolymers and observed that colloidal sols were formed at certain points during his fractional precipitations.

Author : Francisco Balta Calleja
Publisher : CRC Press
Page : 604 pages
File Size : 26,81 MB
Release : 2000-06-09
Category : Technology & Engineering
ISBN : 9780824703820

GET BOOK

A summary of block copolymer chemical structures and synthesis. It discusses physical methods of characterization such as computer simulation, microhardness, dielectric spectroscopy, thermal mechanical relaxation, ultrasonic characterization, transmission electron microscopy, X-ray scattering, and NMR, among others. It also outlines rheological and processing parameters in the multiphase polymer systems with stable microstructures.

Author : J.M.G. Cowie
Publisher : Springer Science & Business Media
Page : 292 pages
File Size : 17,41 MB
Release : 2013-06-29
Category : Technology & Engineering
ISBN : 1475791399

GET BOOK

Examination of the early literature attests to the fact that the study of copolymerization was initiated when polymer science was in its infancy. It has continued to grow to a subject of major importance and has been a source of interest to both academic and industrialist alike. The wide spectrum of structures and properties available in the statistical copolymer has made this a fruitful field of exploration, but one particular and more restricted form which has held its own fascination for many is the limiting case of the strictly alternating copolymer. This is formed, in the ideal situation, when two monomers in a reaction mixture add consecutively to create a polymer chain with a regular {ABABAB} structure, irrespective of the monomer feed ratio. When this happens the resulting copolymer will always have the same composition, a feature which can be advantageous but also somewhat restrictive, as the ability to vary the properties is then limited. Within a series entitled Speciality Polymers it seems appropriate then to deal with this subject, particularly as no previous attempt has been made to draw together the various facets of alternating copolymerization into one volume. It also seems timely to present a more unified picture of the subject which will also illustrate the progress made.

Author : Allen Noshay
Publisher : Elsevier
Page : 533 pages
File Size : 19,46 MB
Release : 2013-10-22
Category : Science
ISBN : 1483218937

GET BOOK

Block Copolymers: Overview and Critical Survey is a critical review of block copolymer technology and a comprehensive critical survey on the synthesis, characterization, properties, and applications of the specific block copolymer structures reported in the literature. The copolymers are organized according to segmental architecture and chemical composition. Comprised of seven chapters, this book begins with an overview of what block copolymers are, how they are made, and what they can and cannot be expected to do. The next chapter defines block copolymers and compares them with other types of polymer "hybrids," that is, polymer blends, random copolymers, and graft copolymers. The various segmental architectures that are possible with block copolymers are then described, followed by a discussion on the various synthesis techniques applicable to block copolymers; the characterization methods capable of elucidating block copolymer structures; some applications of commercially available block copolymers; and some future challenges for block copolymer technology. The last three chapters are devoted to A-B diblock copolymers, A-B-A triblock copolymers, and (A-B)n multiblock copolymers. This monograph should be useful to readers who want to become generally conversant with block copolymer technology and to those who need to delve more deeply into the subject.

Author : Susheel Kalia
Publisher : Springer Science & Business Media
Page : 358 pages
File Size : 12,91 MB
Release : 2013-05-23
Category : Technology & Engineering
ISBN : 3642365663

GET BOOK

Renowned experts give all essential aspects of the techniques and applications of graft copolymers based on polysaccharides. Polysaccharides are the most abundant natural organic materials and polysaccharide based graft copolymers are of great importance and widely used in various fields. Natural polysaccharides have recently received more attention due to their advantages over synthetic polymers by being non-toxic, biodegradable and available at low cost. Modification of polysaccharides through graft copolymerization improves the properties of polysaccharides. Grafting is known to improve the characteristic properties of the backbones. Such properties include water repellency, thermal stability, flame resistance, dye-ability and resistance towards acid-base attack and abrasion. Polysaccharides and their graft copolymers find extensive applications in diversified fields. Applications of modified polysaccharides include drug delivery devices, controlled release of fungicides, selective water absorption from oil-water emulsions, purification of water etc.

Author : L. Sperling
Publisher : Springer Science & Business Media
Page : 438 pages
File Size : 19,3 MB
Release : 2013-03-09
Category : Technology & Engineering
ISBN : 1468428748

GET BOOK

Polymer blends, grafts, and blocks, broadly defined, encompass all of the ways in which two or more kinds of poly mer molecules can be mixed and/or joined. Because these mate rials exhibit non-linear and often synergistic properties, they have found increasing application in our technology. Their multifarious uses have, in turn, spurred new research efforts, to find yet different ways of joining two kinds of polymer molecules, with novel physical and/or mechanical behavior patterns. In August, 1973, the Polymer Division of the American Chemical Society sponsored a symposium at its meeting in Chi cago on Polymer Blends, Grafts, and Blocks. This book collects the papers presented at that symposium. Yet, it is more than just a collection of papers, for we here display the thinking and efforts of a number of top-ranking American and foreign scientists in one of the world's more active research areas. The symposium emphasized the interrelationships among synthetic detail, morphology, and physical and mechanical properties. Several novel syntheses were presented. These include oxidation resistant thermoplastic elastomers (Holden), a graft copolymer based thermoplastic elastomer (Kennedy and Smith), a cationic graft copolymer (Kennedy, Charles, and Davidson), an AB crosslinked copolymer (Bamford and Eastmond), an interpenetrating polymer network (Donatelli, Thomas, and Sperling), and simultaneous interpenetrating networks (Frisch, Klempner, Frisch, and Ghiradella). Most polymer blends, grafts, and blocks exhibit two phases. The theory of microdomain structure was discussed (Helfand). The different ways that the two molecules can be joined together was examined (Kenney), and their topology was explored (Sperling).

Author : S. L. Aggarwal
Publisher : Springer Science & Business Media
Page : 337 pages
File Size : 20,17 MB
Release : 2012-12-06
Category : Technology & Engineering
ISBN : 1468418424

GET BOOK

Block polymers represent another milestone in the preparation of polymers of controlled structure. Catalysts and polymerization methods that allowed the preparation of polymers in which the stereo- and geometric isomerism of the monomer units could be con trolled have indeed been among the major developments in polymer science during the last decade. The synthesis of block polymers, in which the sequence length of the comonomer units can be con trolled, portends equally important developments in the science and technology of polymers. The papers collected in this volume cover primarily the pro ceedings of the most recent symposium on block polymers, sponsored by the Division of Polymer Chemistry of the American Chemical Society. It was held in New York City during the Society's 158th National Meeting in September, 1969. Additional contributions from selected authors were invited especially for this book to achieve the most up-to-date account of the advances that have been made since the development of the thermoplastic elastomers that first brought into focus this important area of research. The first two papers in this volume draw attention to the various problems that should be considered in the preparation of block polymers of precisely defined structure from styrene and butadiene or isoprene by anionic polymerization. Characterization of block polymers presents many problems and there is a paucity of systematic work in this area. Attention has been given to the di lute solution properties of block polymers,however, in one of the papers in this volume.