Advances In Thermotropic Liquid Crystal Polymers

Annotation Liquid crystal polymers are sometimes called super polymers--with good reason. Their wide range of exceptional properties and ease of processing make them design candidates for many demanding applications. This new book provides a thorough review of LCP technology with the emphasis on the chemistry, synthesis and characterization of the material in its many variants. Additional chapters cover processing and applications. From the Editor's Preface The field of thermotropic liquid crystalline polymers has grown substantially in the last two decades, with fundamental research, publications, commercial products, and patents. In the 1980's, Dr. Ralph Miano led my colleagues and me at Hoechst Celanese in commercializing the first thermotropic liquid crystalline polymers, based on Dr. Gordon Calundann's composition patents. Today, more than seven companies have produced thermotropic liquid crystalline polymer materials, with at least 50 variants available. Hence, it is timely to compile a comprehensive review on the nature of this type of material and the ongoing progress in this field€. The goals of this book are to summarize previous work, provide new insights into this class of polymers, and add to the understanding of the formation of liquid crystallinity. This book covers a wide range of topics and addresses different disciplines in the field. The chapters are arranged as a learning scheme for the professional, from basic science to applied engineering. The first few chapters summarize the syntheses of various polyester, polyester-amid, and polyimide liquid crystalline polymers. The science and origins of liquid crystal formation are revealed. Next, we introduce the characterizations of these materials by their different chemical and physical aspects. Because most commercially available thermotropic liquid crystalline polymers have been used in the form of composites, we have also incorporated a chapter on polymer blends, detailing blending mechanisms and resultant properties. Two chapters on thermosetting liquid crystalline polymers integrate them with other topics, because of their unique importance and their applications for microelectronics and packaging. The final chapter deals with the engineering and processing aspects of thermoplastic liquid crystalline polymers for a variety of applications.

This book covers developments in the field of thermotropic liquid crystals and their functional importance. It also presents advances related to different sub-areas pertinent to this interdisciplinary area of research. This text brings together research from synthetic scientists and spectroscopists and attempts to bridge the gaps between these areas. New physical techniques that are powerful in characterizing these materials are discussed.

This volume contains an eclectic collection of 22 papers on liquid crystalline polymers presented at the Sixth Polymer Workshop, in the series sponsored by the European Science Foundation, entitled: 'Liquid Crystal Polymer Systems', in Gentofte, Denmark, 12-14 September 1983. Since a contribution to this volume was strictly voluntary, and in some cases represents a considerably expanded version of that which was presented, it is strictly speaking not correct to term this a 'proceedings'. A description of the aims and purposes of the European Science Foundation with respect to the polymer area has been presented in: Shell Polymers, Vol. 5, No.2, pp. 34-35, 1981. The papers given here represent a cross-section of current research interests in liquid crystalline polymers in the areas of theory, synthesis, characterization, structure-property relationships and applications. At least some of the current interest is motivated by attempts to practically exploit the novel properties of these materials in the developing tech nologies of high strength fibres and advanced materials for constructional purposes, but also for functional materials in the areas of information retrieval, electronics and opto-electronics applications. The editor wishes to thank all those involved for their courtesy and co-operation.

Liquid crystal polymers are sometimes called super polymers--with good reason. Their wide range of exceptional properties and ease of processing make them design candidates for many demanding applications. This new book provides a thorough review of LCP technology with the emphasis on the chemistry, synthesis and characterization of the material in its many variants. Additional chapters cover processing and applications. From the Editor's Preface The field of thermotropic liquid crystalline polymers has grown substantially in the last two decades, with fundamental research, publications, commercial products, and patents. In the 1980's, Dr. Ralph Miano led my colleagues and me at Hoechst Celanese in commercializing the first thermotropic liquid crystalline polymers, based on Dr. Gordon Calundann's composition patents. Today, more than seven companies have produced thermotropic liquid crystalline polymer materials, with at least 50 variants available. Hence, it is timely to compile a comprehensive review on the nature of this type of material and the ongoing progress in this field.... The goals of this book are to summarize previous work, provide new insights into this class of polymers, and add to the understanding of the formation of liquid crystallinity. This book covers a wide range of topics and addresses different disciplines in the field. The chapters are arranged as a learning scheme for the professional, from basic science to applied engineering. The first few chapters summarize the syntheses of various polyester, polyester-amid, and polyimide liquid crystalline polymers. The science and origins of liquid crystal formation are revealed. Next, we introduce the characterizations of these materials by their different chemical and physical aspects. Because most commercially available thermotropic liquid crystalline polymers have been used in the form of composites, we have also incorporated a chapter on polymer blends, detailing blending mechanisms and resultant properties. Two chapters on thermosetting liquid crystalline polymers integrate them with other topics, because of their unique importance and their applications for microelectronics and packaging. The final chapter deals with the engineering and processing aspects of thermoplastic liquid crystalline polymers for a variety of applications.

Advances in Liquid Crystals, Volume I is a collection of papers dealing with lyotropic and thermotropic liquid crystals. One paper discusses lyotropic liquid crystalline phases in systems of amphiphilic compounds, including the liquid crystalline phases, lyotropic liquid crystalline phase, the ""gel"" phases, and the transition between normal and reversed mesophases. Another paper describes the ordering and structure of liquid crystals by reviewing research work on X-ray analysis of thermotropic liquid crystals. One paper explains the studies made on the mesomorphic behavior of block copolymers, including the incompatibility, segregation, and organization of polymers. The paper notes that plastic crystals and liquid crystals are different manifestations of the duality of the melting process in molecular crystals, resulting in the loss of positional and orientation order. One paper describes the essential linear defects found in solid crystals, which have been researched in terms of the major role they play in macroscopic properties, particularly plasticity, as the defects or dislocations of translation. G. Friedel's work classifies liquid crystals into an intermediary symmetry composed of the nematic, the cholesteric, and the smectic phases. This intermediary symmetry occurs between the liquid type symmetry and the solid type symmetry. This collection can prove useful for researchers in liquid crystals and industrial scientists in the field of chemistry and polymer composites.

In recent years, studies by both industry and academic researchers have opened the door to improving performance and reducing costs of these new materials. The particular structure and morphology of LCPs, as well as their peculiar rheological behavior, have stimulated researchers to develop new theoretical models and new characterization and processing techniques to more fully understand and utilize LCPs. Although the scientific literature is very rich in data on the synthetic techniques and on the relations between structure and phase behavior of these new polymers, the understanding of the rheological and processing aspects is still far from satisfactory-particularly in the case of LCP blends. In fact, although an appreciable number of patents and scientific papers have appeared describing the phase behavior, the rheology, and the mechanical properties of many of these polyblends, several aspects of the relations between processing and morphology, and between morphology and properties of these materials are still obscure or even controversial. Now, this new book, written by leading researchers, provides an up-to-date guide and reference to the processing, rheology and applications of pure LCPs and LCP blends. The book concisely reviews the synthetic procedures for the production of LCPs and discusses the rheological behavior and processing methods. Plus, the book examines present and future applications areas of LCPs and LCP blends.

Volume is indexed by Thomson Reuters CPCI-S (WoS). Liquid crystals are substances that have properties which are intermediate between those of a conventional liquid and those of a solid crystal. This special collection comprises peer-reviewed papers that are concerned with all aspects of liquid crystal science and technology. The volume consists of five parts: plenary lectures, the molecular design and synthesis of liquid crystals, the characterization of liquid crystals, the applications of liquid crystals, and the emerging technologies and materials relevant to information display.

Advances in Liquid Crystals, Volume 3 presents some of the applications of liquid crystals, particularly those related to lyotropic and thermotropic liquid crystals. The six articles in this volume cover the development of the theory of electrohydrodynamic properties of liquid crystals; study of lyotropic liquid crystals in the area of surfactants; liquid crystals and foams; the development of ultrasonics in liquid crystal media; and the field of liquid crystals in chromatography. The book will be invaluable to materials engineers, inventors, physicists, and researchers in the field of electronics.