Rheology And Processing Of Liquid Crystal Polymers

Liquid crystal polymers (LCPs) have many strange properties that may be utilized to advantage in the processing of products made from them and their blends with isotropic polymers. This volume (volume 2 in the series Polymer Liquid Crystals) deals with their strange flow behaviour and the models put forward to explain the phenomena that occur in such polymers and their blends. It has been known for some time that small ad ditions of a thermotropic LCP to isotropic polymers not only gives an improvement in the strength and stiffness of the blend but improves the processability of the blend over that of the isotropic polymer. In the case of lyotropic LCPs, it is possible to create a molecular composite in which the reinforcement of an isotropic polymer is achieved at a molecular level by the addition of the LCP in a common solvent. If the phenomena can be fully understood both the reinforcement and an increase in the proces sability of isotropic polymers could be optimized. This book is intended to illustrate the current theories associated with the flow of LCPs and their blends in the hope that such an optimization will be achieved by future research. Chapter 1 introduces the subject of LCPs and describes the ter minology used; Chapter 2 then discusses the more complex phenomena associated with these materials. In Chapter 3, the way in which these phe nomena may be modelled using hamiltonians is fully covered.

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.

Drawing a picture of the current situation of this new field, this volume both summarizes the past achievements and analyzes the present unsolved problems.

Liquid crystal polymers (LCPs) have a wide range of uses, from strong engineering plastics to delicate gels for use in liquid crystal (LC) displays. For this reason, it is essential reading for materials scientists, engineers or technologists in industry, as well as research laboratories or academia. An additional indexed section containing several hundred abstracts from the Rapra Polymer Library database gives useful references for further reading.

This book introduces various applications of liquid crystalline polymers as the emerging new class of high performance novel materials. The authors detail the advantageous properties of these LCs including optical anisotropic, transparency and easy control over structure. This interdisciplinary work includes valuable input from international projects with special focus on the use of liquid crystalline polymers and/or nanocomposites.

An Introduction to Polymer Rheology and Processing is a practical desk reference providing an overview of operating principles, data interpretation, and qualitative explanation of the importance and relationship of rheology to polymer processing operations. It covers full-scale processing operations, relating industrial processing operations and design methodology to laboratory-scale testing. Hundreds of design formulas applicable to scaling up the processing behavior of polymeric melts are presented. The book also provides a "working knowledge" description of major rheological test methods useful in product development and includes a useful glossary of polymer and test method/instrumentation definitions. Lavishly illustrated and featuring numerous sample calculations and modeling approaches, An Introduction to Polymer Rheology and Processing is a "must have" book for polymer engineers and rheologists.

Rheology is the study of the flow of matter, primarily in the liquid state, but also as 'soft solids' or solids under flow conditions in which they respond with plastic flow rather than deforming elastically in response to the applied force. An understanding of the flow of matter underpins a diversity of technologies and industrial processing including polymer and food processing. It applies to substances which have a complex microstructure, such as concentrated solutions, suspensions, polymers and inorganic glass formers as well as biological materials which belong to the class of soft matter. Rheological measurements are seemingly straightforward to make, but require models to interpret the mechanical measurements in terms of the microscopic behaviour of the material. This boo draws these diverse strands of current rheological research in to a single volume which embraces theory, measurement and applications in topics as diverse as theory and electrospinning, coal ash slag and food processing, hydrogels and liquid crystal polymers, reaction injection moulding and microreheology.There is a strong focus on the emerging topics in rheology and its application to complex soft matter especially in the field of food science and technology. The sixteen chapters in the volume present unpublished research work across these topics from leading authorities in the relevant field. The volume has a strong international representation with the selected authors drawn from some ten countries in Europe, South America and the rest of the world. Each chapter contains a comprehensive bibliography of related work. The book provides a fascinating snap shot across the current developments in rheology.