A.A. Collyer – författare

As well as providing an introduction to the rapidly-changing face of rheological measurement, with particular regard to process control, this book increases awareness of the greater variety of techniques currently available for understanding the way in which fluids behave during processing. This book should be of interest to materials scientists, engineers or technologists in industry and research laboratories.

Rubber Toughened Engineering Plastics covers the main physical principles involved in optimum toughening in high temperature engineering plastics and speciality plastics and describes the synthetic strategies used to obtain satisfactorily toughened grades in these materials by control of microstructure. This book will act as a focus for current thought on the principles of rubber toughening and the methods employed for the rubber toughening of major engineering and speciality plastics.

This book explains the principles underlying the flow of liquid crystal polymers and of blends involving these materials, and how the rheological properties influence processing behaviour. It is assumed that the reader is familiar with rheology but not with liquid crystalline polymers. It is written by an international group of authors.

In an area as vast and important as rheology, it is essential that the experimentalist understands the underlying theories and shortcomings of the measurement technique used, that they are aware of the likely microstructure of the fluid under study and that from this they can appreciate how the fluid and the measuring system interact with each other. This major handbook, written by an international group of experts in the range of rheological techniques, presents the state of the art in rheological measurement, and concentrates on the techniques and underlying physical principles. The second edition, fully revised and updated to include new techniques is invaluable to polymer and materials scientists, engineers and technologists, and anyone else making rheological measurements on materials whether they be polymeric, biological, slurries, food or other complex fluids.

Helps the individual without formal training in plastic materials through the maze of materials selection to his final goal. Those with a basic knowledge of this area will benefit from the more practical aspects of the guide.

The topics covered in this book may be divided into radiation effects on polymers, test methods, radiation processing and other applications of ionizing radiation.

The subject of liquid crystals and their use in electronic displays and in non-linear optical systems has become of tremendous importance during the last decade; and the incorporation of liquid crystal units into polymeric materials has led to a group of new materials with diverse properties. Some of these properties have been utilized in new products and some have yet to be used. Much published work has appeared that deals with specific materials or particular applications, and it was felt that a book was needed to examine and explain the underlying principles governing the diverse properties of these liquid crystal polymers, LCPs. The current work describes the diverse nature of LCPs, their synthesis, characterization, properties and finally their applications. It describes the manner in which liquid crystallinity or mesomorphism occurs in small molecules, monomer liquid crystals and polymer liquid crystals. Chapter 1 gives a classification of the various ways in which the meso­ gens may be connected to the polymer chains. Currently, the bulk of LCP material is based on main chain or longitudinal LCPs for use in engineering applications. The side chain or comb polymers are intended for use in electronics and opto-electronic systems and as surfactants. Many other variants and possibilities exist but their properties have not yet been fully studied or used. In this respect it is hoped that the current work will indicate future possibilities as well as discussing current opinion. v Preface vi Chapters 2 and 3 describe methods of characterizing the mesophases.

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.

The reinforcement of materials such as mud and clay by hair, straw and vegetable fibres has been long established in man''s history, enabling him to improve his buildings and extend his engineering abilities. With the advent of modern synthetic polymers it was rapidly realised that the addition of fibres, flakes and particulate materials to polymer matrices could improve mechanical properties significantly. Fibres and flakes are the most effective and have enabled several polymers with limited properties to compete with long-established metallic materials, reSUlting in cost, weight and processing economies. This is increasingly apparent in the selection of materials for aerospace and road vehicle applications as well as in a multitude of domestic products. Reinforced plastics, both thermosets and thermoplastics, are used in increasingly harsh environments involving elevated temperatures and aggressive conditions. Fibre reinforcement of thermoplastics dominates, and a pattern of increasing replacement of fibre reinforced thermosets by reinforced thermoplastics is emerging. This trend is encouraged by the development of continuous fibre reinforced grades of the newer high-temperature engineering thermoplastics such as polyether ether ketone. The first part of this book reviews the mechanical properties and theories of short fibre reinforcement. The principal reinforcements are reviewed and a separate chapter is devoted to the uses of natural fibres as reinforcements for thermoplastics. This is an interesting and commercially important area, especially for Third World countries v vi Preface where these fibres are grown but are facing severe competition from synthetic fibres in traditional applications such as ropes and matting.

Rubber Toughened Engineering Plastics covers the main physical principles involved in optimum toughening in high temperature engineering plastics and speciality plastics and describes the synthetic strategies used to obtain satisfactorily toughened grades in these materials by control of microstructure. This book will act as a focus for current thought on the principles of rubber toughening and the methods employed for the rubber toughening of major engineering and speciality plastics.

In an earlier book, Rheological Measurement (A. A. Collyer & D. W. Clegg, Elsevier Applied Science, 1988), the basic rheological methods of measurement presently used were discussed in the light of the basic underlying principles and current theories. The same approach is adopted in this companion book, which is concerned with some newer or more sophisticated techniques that have resulted from a fresh understanding of the subject, or as a result of improvement in computer control, data acquisition and computational power, or more simply from an industrial need, particularly with regard to process control. The first two chapters deal with the extensional flow properties of fluids and their measurement. This inclusion is in response to a greater awareness in industry of the importance of these flows. Chapter 3 intro­ duces and develops the subject of surface rheology and the measurement of its properties, again a subject of increasing significance. The methods of measurement of the dynamic mechanical properties of fluids and the calculation of the resulting rheological parameters are discussed in Chap­ ters 4-7 inclusive. The subject areas covered are: large-amplitude oscilla­ tory shear, a model for viscoelastic fluids and solids, a new method of measuring dynamic mechanical properties, particularly for curing sys­ tems, and the use of complex waveforms in dynamic mechanical analysis.

In an area as vast and important as rheology, it is essential that the experimentalist understands the underlying theories and shortcomings of the measurement technique used, that they are aware of the likely microstructure of the fluid under study and that from this they can appreciate how the fluid and the measuring system interact with each other. This major handbook, written by an international group of experts in the range of rheological techniques, presents the state of the art in rheological measurement, and concentrates on the techniques and underlying physical principles. The second edition, fully revised and updated to include new techniques is invaluable to polymer and materials scientists, engineers and technologists, and anyone else making rheological measurements on materials whether they be polymeric, biological, slurries, food or other complex fluids.

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.

The reinforcement of materials such as mud and clay by hair, straw and vegetable fibres has been long established in man's history, enabling him to improve his buildings and extend his engineering abilities. With the advent of modern synthetic polymers it was rapidly realised that the addition of fibres, flakes and particulate materials to polymer matrices could improve mechanical properties significantly. Fibres and flakes are the most effective and have enabled several polymers with limited properties to compete with long-established metallic materials, reSUlting in cost, weight and processing economies. This is increasingly apparent in the selection of materials for aerospace and road vehicle applications as well as in a multitude of domestic products. Reinforced plastics, both thermosets and thermoplastics, are used in increasingly harsh environments involving elevated temperatures and aggressive conditions. Fibre reinforcement of thermoplastics dominates, and a pattern of increasing replacement of fibre reinforced thermosets by reinforced thermoplastics is emerging. This trend is encouraged by the development of continuous fibre reinforced grades of the newer high-temperature engineering thermoplastics such as polyether ether ketone. The first part of this book reviews the mechanical properties and theories of short fibre reinforcement. The principal reinforcements are reviewed and a separate chapter is devoted to the uses of natural fibres as reinforcements for thermoplastics. This is an interesting and commercially important area, especially for Third World countries v vi Preface where these fibres are grown but are facing severe competition from synthetic fibres in traditional applications such as ropes and matting.

Rubber Toughened Engineering Plastics covers the main physical principles involved in optimum toughening in high temperature engineering plastics and speciality plastics and describes the synthetic strategies used to obtain satisfactorily toughened grades in these materials by control of microstructure. This book will act as a focus for current thought on the principles of rubber toughening and the methods employed for the rubber toughening of major engineering and speciality plastics.

The subject of liquid crystals and their use in electronic displays and in non-linear optical systems has become of tremendous importance during the last decade; and the incorporation of liquid crystal units into polymeric materials has led to a group of new materials with diverse properties. Some of these properties have been utilized in new products and some have yet to be used. Much published work has appeared that deals with specific materials or particular applications, and it was felt that a book was needed to examine and explain the underlying principles governing the diverse properties of these liquid crystal polymers, LCPs. The current work describes the diverse nature of LCPs, their synthesis, characterization, properties and finally their applications. It describes the manner in which liquid crystallinity or mesomorphism occurs in small molecules, monomer liquid crystals and polymer liquid crystals. Chapter 1 gives a classification of the various ways in which the meso­ gens may be connected to the polymer chains. Currently, the bulk of LCP material is based on main chain or longitudinal LCPs for use in engineering applications. The side chain or comb polymers are intended for use in electronics and opto-electronic systems and as surfactants. Many other variants and possibilities exist but their properties have not yet been fully studied or used. In this respect it is hoped that the current work will indicate future possibilities as well as discussing current opinion. v Preface vi Chapters 2 and 3 describe methods of characterizing the mesophases.

In an earlier book, Rheological Measurement (A. A. Collyer & D. W. Clegg, Elsevier Applied Science, 1988), the basic rheological methods of measurement presently used were discussed in the light of the basic underlying principles and current theories. The same approach is adopted in this companion book, which is concerned with some newer or more sophisticated techniques that have resulted from a fresh understanding of the subject, or as a result of improvement in computer control, data acquisition and computational power, or more simply from an industrial need, particularly with regard to process control. The first two chapters deal with the extensional flow properties of fluids and their measurement. This inclusion is in response to a greater awareness in industry of the importance of these flows. Chapter 3 intro­ duces and develops the subject of surface rheology and the measurement of its properties, again a subject of increasing significance. The methods of measurement of the dynamic mechanical properties of fluids and the calculation of the resulting rheological parameters are discussed in Chap­ ters 4-7 inclusive. The subject areas covered are: large-amplitude oscilla­ tory shear, a model for viscoelastic fluids and solids, a new method of measuring dynamic mechanical properties, particularly for curing sys­ tems, and the use of complex waveforms in dynamic mechanical analysis.

In an area as vast and important as rheology, it is essential that the experimentalist understands the underlying theories and shortcomings of the measurement technique used, that they are aware of the likely microstructure of the fluid under study and that from this they can appreciate how the fluid and the measuring system interact with each other. This major handbook, written by an international group of experts in the range of rheological techniques, presents the state of the art in rheological measurement, and concentrates on the techniques and underlying physical principles. The second edition, fully revised and updated to include new techniques is invaluable to polymer and materials scientists, engineers and technologists, and anyone else making rheological measurements on materials whether they be polymeric, biological, slurries, food or other complex fluids.

In many cases rheological measurements are carried out in the simplest of geometries, but the interpretation involved in obtaining the rheological parameters of the test fluids from these measurements is surprisingly complex. The purpose of this book is to emphasise the points on which most workers in the field agree, and to let the authors deal with the contentious points according to their own beliefs and experience. This work represents a summary of the current thought on rheological meas­ urement by experts in the various techniques. When making measurements and obtaining from them parameters that describe the flow behaviour of the test fluids, it is essential that the experimentalist understands the underlying theory and shortcomings of the measurement technique, that he is aware of the likely microstructure of the fluid, and that from this he can appreciate how the fluid and the measuring system will interact with each other. It is this interaction that gives both the required rheological parameters of the fluids and the artefacts that confuse the issue. This book covers the main rheological measurement techniques from capillary, slit and stretching flows to rotational and oscillatory rheometry in various geometries including sliding plate measurements. These topics are backed up by chapters on more practical aspects, such as commercial instruments, and on computer control and data acquisition. The chapters deal with the basic methods, how the measurements are taken, and what assumptions and interpretations are made to obtain valid data on the test fluids.