Polymers and polymer composites have been increasingly used in place of metals for various industries; namely, aerospace, automotive, bio-medical, computer, electronhotograohy, fiber, and rubber tire. Thus, an understanding of the interactions between polymers and between a polymer and a rigid counterface can enhance the anplications of polymers under various environments. In meet ing this need, polymer tribology has evolved to deal with friction, lubrication and wear of polymeric materials ann to anSwer some of the problems related to polymer-polymer interactions or nolymer rigid body interactions. The purpose of this first International Symposium was to introduce advances in studies of polymer friction and wear, especially in Britain and the U. S. S. R. Most earlier studies of the Fifties were stimulated by the growth of rubber tire industries. Continuous research through the Sixties has broadened the base to include other polymers such as nylon, polyolefins, and poly tetra fluoroethylene, or PTFE. However, much of this work was published in engineering or physics journals and rarely in chemistry journals: presumably, the latter have always considered the work to be too applied or too irrelevant."

Injection moulding is one of the most important methods of manufacturing plastics products. Through the development of sophisticated micro processor control systems, the modern injection moulding machine is capable of producing precision mouldings with close tolerances in large numbers and with excellent reproducibility. This capability, however, is often limited by the lack of a proper appreciation of mould design. The mould, or tool as it is often called, is at the heart of the injection moulding process. Its basic function is to accept the plastic melt from the injection unit and cool it to the desired shape prior to ejection. It is not, however, simply a matter of the mould having an impression of the shape to be moulded. Many other factors have to be taken into account - for example, the ability to fill the mould impression properly and efficiently without inducing weaknesses in the moulding and the efficient cooling of the moulding in order to maximise production rates without diminishing the quality of the moulding. In addition, the type of mould, gate and runner system, and ejection system which will best meet the needs of a particular job specification have to be determined. In our experience lack of attention to such factors leads to the mould limiting the ability of the injection moulding machine and preventing the process as a whole from achieving its true potential.

In the first half of this century, great strides were made in under standing the behavior of polymers in dilute solutions or in the solid state. Concentrated solutions, on the other hand, were commonly regarded as mainly of interest to practitioners, being too complex for the rigorous application of statistical theory. Given the preoccupation with the isolated polymer molecule and the attendant focus on the state of infinite dilution, it is not surprising that aggregation, and inter-polymer associ ation in general, was the bugaboo of experimentalists. These attitudes have changed remarkably over the last few decades. The application of sealing theory to polymer solutions has stimulated investigation of the semi-dilute state, and the region between infinite dilution and swollen gel is no longer perceived as terra incognita. New techniques, such as dynamic light scattering, have proven to be of much value in such investigations. At the same time, it has become clear that consideration of strong inter- and intra-polymer forces, superimposed on the familiar description of the statistical chain, is prerequisite to the application of polymer science to numerous systems of interest. Para mount among these, of course, are biopolymers, their complexes and assemblies. The isolated random coil must be viewed as tl rarity in nature."

Because of the many important new developments in other branches of science, some scientists fail to recognize that the volume of polyolefins produced annually is greater than that of all metals. Hence, the American Chemical Society s"ponsored symposia on the History of Polyolefins at its national meeting at Miami Beach in the Spring of 1985 and a Macromolecular Secretariat on Advances in Polyolefins at its national meeting in Chicago in the fall of that year. The books on the proceedings of these landmark symposia and another book entitled "The Chain Straighteners" by Dr. F. M. McMillan will provide the scientist with background information which is essential for re- searchers in this important phase of polymer science. The presentations at these international symposia and the publica- tions of the reports presented, would not be possible without the dedicated efforts of our assistant editors and publisher. The list of contributors to ADVANCES IN POLYOLEFINS includes most of the leaders in this field, such as Dr. Mark, Mandelkern, Bruzzone, Hsieh, Kaneda, Chien, Tait, Karol, Kaminisky, Scott, Cook, Mirabella, Samuels, Kanamoto and Vigo. These reports covered many phases of polyolefin science and technol- ogy, ranging from elastomers, single crystals, film and fibers to char- acterizations by modern instrumentation and many new innovations in catalysis which have brought about a revolution in polyolefin production.

The fluorine atom, by virtue of its electronegativity, size, and bond strength with carbon, can be used to create compounds with remarkable properties. Small molecules containing fluorine have many positive impacts on everyday life of which blood substitutes, pharmaceuticals, and surface modifiers are only a few examples. Fluoropolymers, too, while traditionally associated with extreme hi- performance applications have found their way into our homes, our clothing, and even our language. A recent American president was often likened to the tribology of PTFE. Since the serendipitous discovery of Teflon at the Dupont Jackson Laboratory in 1938, fluoropolymers have grown steadily in technological and marketplace importance. New synthetic fluorine chemistry, new processes, and new apprec- tion of the mechanisms by which fluorine imparts exceptional properties all contribute to accelerating growth in fluoropolymers. There are many stories of harrowing close calls in the fluorine chemistry lab, especially from the early years, and synthetic challenges at times remain daunting. But, fortunately, modern techniques and facilities have enabled significant strides toward taming both the hazards and synthetic uncertainties. In contrast to past environmental problems associated with fluorocarbon refrigerants, the exceptional properties of fluorine in polymers have great environmental value. Some fluoropolymers are enabling green technologies such as hydrogen fuel cells for automobiles and oxygen-selective membranes for cleaner diesel combustion.

Proceedings of the International Symposium on Polymer Therapeutics - Recent Progress in Clinics and Future Prospects, held July 13-14, 2001, in Nara, Japan. The technology of polymer science has developed considerably during the past half-century, and this volume describes some of the aspects of this technology that will have a great impact in the future. Among these advances, for example, are gene delivery to specific disease sites and carrier polymers that respond to a stimulus or particular environment. Cancer targeted drug delivery is another focused area of this volume because of the important nature of EPR-effect of polymer drugs in tumor. Included are discussions of as many examples as possible of polymer drugs that have achieved, or are close to clinical use. The concept of "Polymer drugs" here is limited to primarily injectable and water-soluble agents, although also covered are some drugs in micellar form or liposomes. This book is intended for students and researchers in the field of pharmacology who have particular interests in drug delivery, targeting, and formulation, as well as for clinicians such as oncologists who are interested in the field. People who work at regulatory agencies should also be aware such that drugs with great potential are being developed and will be beneficial to many patients, as well as to health insurance agencies because of improved cost effectiveness.

The liquid crystalline state may be identified as a distinct and unique state of matter which is characterised by properties which resembles those of both solids and liquids. It was first recognised in the middle of the last century through the study of nerve myelin and derivatives of cholesterol. The research in the area really gathered momentum, however, when as a result of the pioneering work of Gray in the early 1970's organic compounds showing liquid crystalline properties were shown to be suitable to form the basis of display devices in the electronic products. The study of liquid crystals is truly multidisciplinary and has attached the attention of physicists, biologists, chemists, mathematicians and electronics engineers. It is therefore impossible to cover all these aspects fully in two small volumes and therefore it was decided in view of the overall title of the series to concentrate on the structural and bonding aspects of the subject. The Chapters presented in these two volumes have been organised to cover the following fundamental aspects of the subject. The calculation of the structures of liquid crystals, an account of their dynamical properties and a discussion of computer simulations of liquid crystalline phases formed by Gay Berne mesogens. The relationships between molecular conformation and packing are analysed in some detail. The crystal structures of liquid crystal mesogens and the importance of their X ray scattering properties for characterisational purposes are discussed.

Thepolymerizationofole nsanddi-ole nsisoneofthemostimportanttargets inpolymerscience.Thisreviewarticledescribesrecentprogressinthis eldand deals with organo-transition metal complexes as polymerization catalysts. - cent developments in organometallic chemistry have prompted us to nd a precise description of the mechanism of propagation, chain transfer, and terminationstepsinthehomogeneouslymetal-assistedpolymerizationofole ns anddiole ns.Thus,thisdevelopmentprovidesanideafordesigninganycatalyst systems that are of interest in industry. Recently,the agostic interactionofalkylgroup(s)ontransitionmetalshas emerged as highly basic and new concept and is found to be important in understandingthemechanismofthemetal-catalyzedhomogeneousoligomer- ation and polymerization of a-ole ns. Early transition metal alkyl complexes generallyhavepartiallyionicM-C bondsandshowa-agostichydrogeninter- tion that somewhat stabilizes the catalytically active species by providing el- tronsatavacantsite onthe metal.Thisisinsharp contrasttothefactthatlate transition metal alkyl complexes show mainly b-agostic hydrogen interaction that causes the hydrogen transfer easily through b-hydrogen elimination and reductive elimination, and that gives rise to the oligomerization of ole ns. Organometalliccomplexesoftheearlyandlatetransitionmetalshavebeenused as catalysts for ole n oligomerization and polymerization. The mechanism involved in these catalyst systems depends very much upon the kind of metal centersaswellastheirco-ligands,andthusthedi?erentmechanismswhichcan bedistinguishedbydetailedinvestigationsshouldbeassumedforearlyandlate transition metal catalysts. In this contribution, we review the mechanism of polymerization and oligomerization involving early transition metals, taking as our basis recent resultsinadvancedorganometallicchemistry.Firstofall,somerecentexamples of the previous reviews concerning the Ziegler-Natta polymerization are cited [1-10]. Then, relevant new reports are surveyed in a systematic fashion.

Soft matter and biological systems pose many challenges for theoretical, experimental and computational research. From the computational point of view, these many-body systems cover variations in relevant time and length scales over many orders of magnitude. Indeed, the macroscopic properties of materials and complex fluids are ultimately to be deduced from the dynamics of the microsopic, molecular level. In these lectures, internationally renowned experts offer a tutorial presentation of novel approaches for bridging these space and time scales in realistic simulations. This volume addresses graduate students and nonspecialist researchers from related areas seeking a high-level but accessible introduction to the state of the art in soft matter simulations.

In the modern organic synthesis industries, one of which is the synthetic rubber industry, ever increasing use is made of physical and physicochemical methods of analysis, which sur pass chemical methods in speed, accuracy, and sensitivity. By these methods it is often possible to arrive at the solution of problems in the investigation of complex mixtures of organic products which are not amenable to the usual chemical methods of analysis. One such physical method is ultraviolet spectrophotometry. The field of application of this method is restricted, in the main, to aromatic compounds and to systems containing double bonds conjugated among themselves or with functional groups. In the synthetic rubber industry ultraviolet spectroscopy finds appli cation in the analysis of a great variety of substances used in that industry: for the determination of impurities in monomers and intermediate products, in the study of the composition of certain polymers, for the quantitative estimation of various ingredients in rubbers, in the control of certain copolymeriza tion processes, and for many other purposes. The method can be used for the identification of certain compounds and can be applied in the determination of the composition of syn thetic rubber samples. Shortcomings of the method, which limit its analytical application in certain cases, are the super position of absorption spectra and their inadequate selectivity."

One of the most significant challenges facing mankind in the twenty-first century is the development of a sustainable global economy. Within the scientific community, this calls for the development of processes and technologies that will allow the sustainable production of materials from renewable natural resources. Plant material, in particular lignin, is one such resource. During the annual production of about 100 million metric tons of chemical wood pulps worldwide, approximately 45 and 2 million metric tons/year of kraft lignin and lignosulfonates, respectively, are also generated. Although lignosulfonates have found many applications outside the pulp and paper industry, the majority of kraft lignin is being used internally as a low-grade fuel for the kraft pulping operation. A surplus of kraft lignin will become available as kraft mills increase their pulp production without expanding the capacity of their recovery boilers that utilize lignin as a fuel. There is a tremendous opportunity and an enormous economic incentive to find better uses of kraft lignin, lignosulfonates and other industriallignins. The pulp and paper industry not only produces an enormous amount of lignins as by products of chemical wood pulps, but it also utilizes about 10 million metric tons of lignin per year as a component of mechanical wood pulps and papers. Mechanical wood pulps, produced in a yield of 90-98% with the retention of lignin, are mainly used to make low-quality, non-permanent papers such as newsprint and telephone directories because of the light-induced photooxidation of lignin and the yellowing of the papers.

Making Flory-Huggins Practical: Thermodynamics of Polymer-Containing Mixtures, by B. A. Wolf * Aqueous Solutions of Polyelectrolytes: Vapor-Liquid Equilibrium and Some Related Properties, by G. Maurer, S. Lammertz, and L. Ninni Schafer * Gas-Polymer Interactions: Key Thermodynamic Data and Thermophysical Properties, by J.-P. E. Grolier, and S. A.E. Boyer * Interfacial Tension in Binary Polymer Blends and the Effects of Copolymers as Emulsifying Agents, by S. H. Anastasiadis * Theory of Random Copolymer Fractionation in Columns, by Sabine Enders * Computer Simulations and Coarse-Grained Molecular Models Predicting the Equation of State of Polymer Solutions, by K. Binder, B. Mognetti, W. Paul, P. Virnau, and L. Yelash * Modeling of Polymer Phase Equilibria Using Equations of State, by G. Sadowski

The three sections of this volume deal with topics of broad interest. The first deals with cetyl alcohol and is a most comprehensive study of this essential ingredient in the cosmetic and pharmaceutical industry, with an explanation of its functionality. The second is a most comprehensive, up-to-date review of acid/base interactions of a variety of materials, including small molecules, proteins and polyelectrolytes. The third section describes the combined radiochemical and electrochemical methods in the evaluation of the properties of solids in contact with solutions.

Crystalline or, more properly, semi-crystalline polymers continue to present major challenges and opportunities to scientists and technologists alike. On the one hand, scientific understanding of their structure and properties still lags behind that of other economically important, but less complicated materials. On the other hand, there remains very considerable potential for improving properties in systems designed for specific pur poses. Ways are only just being found of transferring inherent molecular properties (such as high modulus) to the macromolecular solid. Beyond these are many possibilities of manipulating the organization of chemical and physical textures towards desired ends. The chapters in this volume are reports, by wen-known and active researchers, on some of the important recent developments ofthese themes. Grubb begins with the fundamental and central problem of determining polymeric microstructure. Polymers sutTer by comparison with other materials in that it has not generany been possible to exploit the high resolution of the electron microscope to determine their microstructure in adequate detail. However, recently, ways have been found of studying representative lamellar textures in melt-crystallized polymers. When fully exploited these must add greatly to our detailed knowledge and provide a firmer fundamental base for future developments. Radiation damage bears the primary responsibility for restricting electron microscopy. In his chapter, Kener recounts how appreciation of this fact led him into a fascinating study of ever deeper aspects of radiation damage in polyethylene over two decades, often controversiany but invariably clarifying the basic understanding of an area now of increasing commercial importance."

These volumes, 7 and 8, of Fracture Mechanics of Ceramics constitute the proceedings of an international symposium on the fracture mechanics of ceramic materials held at Virginia Polytechnic Institute and State University, Blacksburg, Virginia on June 19, 20 and 21, 1985. These proceedings constitute the fourth pair of volumes of a continuing series of conferences. The theme of this conference, as the previous three, focused on the mechanical behavior of ceramic materials in terms of the characteristics of cracks, particularly the roles which they assume in the fracture process. The 78 contributed papers by over 100 authors and co-authors represent the current state of the field. They address many of the theoretical and practical problems of interest to those concerned with brittle fracture. The program chairmen gratefully acknowledge the financial assistance for the Symposium provided by the EXXON Foundation, the Army Research Office, the National Science Foundation, and the Office of Naval Research. Without their support, this conference simply would not have been possible. The suggestions of Drs. J. C. Hurt, R. C. Pohanka, and L. Toth were particularly helpful in assuring the" success of this symposium. Special appreciation is extended to Professor J. I. Robertson, C. P. Miles Professor of History, whose presentation following the banquet on the American Civil War was very well received by the audience. Finally, we wish to also thank our joint secretaries, especially Karen Snider, for their patience and help in finally bringing these proceedings to press.

This work is a collection of short reviews on membranes and transport. It portrays the field as a mosaic of bright little pieces, which are interesting in themselves but gain full signif icance when viewed as a whole. Traditional boundaries are set aside and biochemists, biophysicists, physiologists, and cell biologists enter into a natural discourse. The principal motivation of this work was to ease the problems of communication that arose from the explosive growth and interdisciplinary character of membrane research. In these volumes we hope to provide a readily available comprehensive source of critical information covering many of the exciting, recent developments on the structure, biosyn thesis, and function of biological membranes in microorganisms, animal cells, and plants. The 182 reviews contributed by leading authorities should enable experts to check up on recent developments in neighboring areas of research, allow teachers to organize material for membrane and transport courses, and give advanced students the opportunity to gain a broad view of the topic. Special attention was given to developments that are expected to open new areas of investigation. The result is a kaleidoscope of facts, viewpoints, theories, and techniques, which radiates the excitement of this important field. Publication of these status reports every few years should enable us to follow progress in an interesting and easygoing format. I am grateful to the authors, to Plenum Publishing Corporation, and to several of my colleagues for their thoughtful suggestions and enthusiastic cooperation, which made this work possible.

Polymeric Nanoparticles of Chitosan Derivatives as DNA and siRNA Carriers, by Y. K. Kim, H. L. Jiang, Y. J. Choi, I. K. Park, M. H. Cho and C. S. Cho.- Chitosan and Its Derivatives for Drug Delivery Perspective, by T. A. Sonia and C. P. Sharma.- Chitosan-based Nanoparticles in Cancer Therapy, by V.-K. Lakshmanan, K. S. Snima, J. D. Bumgardner, S. V. Nair, and R. Jayakumar.- Chitosan and Thiolated Chitosan, by F. Sarti and A. Bernkop-Schnurch.- Chitosan-Based Particulate Systems for Non-Invasive Vaccine Delivery, by S. enel.- Multifunctional Chitosan Nanoparticles for Tumor Imaging and Therapy, by J. Y. Yhee, Heebeom Koo, Dong Eun Lee, Kuiwon Choi, Ick Chan Kwon and Kwangmeyung Kim.- Chitosan-Coated Iron Oxide Nanoparticles for Molecular Imaging and Drug Delivery, by H. Arami, Z. Stephen, O. Veiseh and M. Zhang.- Chitosan: Its Applications in Drug-Eluting Devices, by Mei -Chin Chen, Fwu -Long Mi, Zi -Xian Liao and Hsing -Wen Sung.-"

Polymeric Bionanocomposites as Promising Materials for Controlled Drug, by M. Prabaharan, R. Jayakumar; Chitosan and Chitosan Derivatives in Drug Delivery and Tissue Engineering, by R. Riva, H. Ragelle, A. des Rieux, N. Duhem, C. Jerome, and V. Preat; Chitosan: A Promising Biomaterial for Tissue Engineering Scaffolds, by P. K. Dutta, K. Rinki and J. Dutta; Chitosan-Based Biomaterials for Tissue Repair and Regeneration, by X. Liu, L. Ma, Z. Mao and C. Gao; Use of Chitosan as a Bioactive Implant Coating for Bone-Implant Applications, by M. R. Leedy, H. J. Martin, P. A. Norowski, J. A. Jennings, W. O. Haggard, and J.D. Bumgardner; New Techniques for Optimization of Surface Area and Porosity in Nanochitins and Nanochitosans, by R. A. A. Muzzarelli; Production, Properties and Applications of Fungal Cell Wall Polysaccharides: Chitosan and Glucan, by N. New, T. Furuike, and H. Tamura;"