Low Temperature Thermal Expansion Of Plastics

Low-Temperature Properties of Polymers systematizes the available materials on polymers. This book also describes the main trends in the investigation of interrelated properties of polymers, such as thermal (heat capacity, thermal conductivity, and thermal expansion), acoustical, dielectric, and viscoelastic, which maintain the physical properties of polymers at low temperatures. Comprised of nine chapters, this book first covers heat capacity of polymers at low temperature, and then tackles thermal conductivity of polymers at low temperatures. Chapter 3 discusses thermal expansion of polymers at low temperatures, and Chapter 4 tackles electrical properties of polymers at low temperatures. The fifth chapter covers nuclear magnetic resonance in polymers at low temperature, while the succeeding chapter encompasses dynamic mechanical properties of polymers at low temperatures. Chapter 7 concerns itself with the acoustical properties of polymers at low temperatures, while the succeeding chapter covers viscoelastic parameters of polymers at low temperatures. The closing chapter covers how to determine the thermophysical characteristics of polymers by acoustic measurement at helium temperature. This book will be of great interest to researchers or professionals whose line of work involves the manipulation and understanding of the properties of polymers.

A summary is presented of a research program aimed at the improvement of high-temperature strain gages of the electrical resistance type. Potential ceramic and metal components were evaluated and a gage was devised that was based on these evaluations. This gage (NBS 5B) was flexible and easy to install; however, it lacked resistance stability at higher temperatures. In an attempt to minimize this deficiency, ceramic cements were developed that showed greater electrical resistivity than had been previously observed in the range 800 to 1800 degrees Fahrenheit; also, a technique was devised for increasing the resistance to ground by applying a fired-on ceramic coating to the grid of a specifically developed unbacked gage. A study was made of the cause of the erratic response of cemented gages that had not been preheated prior to use. There were strong indications that the erratic response was caused mostly by the rapid decrease in resistance that accompanied structural changes in the cement.

The birth of this monograph is partly due to the persistent efforts of the General Editor, Dr. Klaus Timmerhaus, to persuade the authors that they encapsulate their forty or fifty years of struggle with the thermal properties of materials into a book before they either expired or became totally senile. We recognize his wisdom in wanting a monograph which includes the closely linked properties of heat capacity and thermal expansion, to which we have added a little 'cement' in the form of elastic moduli. There seems to be a dearth of practitioners in these areas, particularly among physics postgraduate students, sometimes temporarily alleviated when a new generation of exciting materials are found, be they heavy fermion compounds, high temperature superconductors, or fullerenes. And yet the needs of the space industry, telecommunications, energy conservation, astronomy, medical imaging, etc. , place demands for more data and understanding of these properties for all classes of materials - metals, polymers, glasses, ceramics, and mixtures thereof. There have been many useful books, including Specific Heats at Low Tempera tures by E. S. Raja Gopal (1966) in this Plenum Cryogenic Monograph Series, but few if any that covered these related topics in one book in a fashion designed to help the cryogenic engineer and cryophysicist. We hope that the introductory chapter will widen the horizons of many without a solid state background but with a general interest in physics and materials.

This book provides a simplified, practical, and innovative approach to understanding the design and manufacture of plastic products in the World of Plastics. The concise and comprehensive information defines and focuses on past, current, and future technical trends. The handbook reviews over 20,000 different subjects; and contains over 1,000 figures and more than 400 tables. Various plastic materials and their behavior patterns are reviewed. Examples are provided of different plastic products and relating to them critical factors that range from meeting performance requirements in different environments to reducing costs and targeting for zero defects. This book provides the reader with useful pertinent information readily available as summarized in the Table of Contents, List of References and the Index.

This, the second special topical conference on the properties of Non-Metallic Materials at Low Temperatures, was sponsored by the International Cryogenic Materials Conference Board. The potential for plastics materials in the field of cryogenics is vast and as yet only partly explored. In addition, many other materials, which qualify for the title non-metallic but are not 'plastics', have numerous possible outlets in low temperature technology. This conference aimed at providing a forum, whereby specialists from Industry, the Universities and from Government sponsored Institutions could assemble to discuss the extent of our current knowledge. As it transpired, the meeting was also to high light the considerable gaps that still exist in our fundamental understanding of the low temperature behaviour of these materials. On this theme, during the course of the conference, a reference was made to an almost forgotten quotation by Lord Kelvin, who said: "When you cannot measure what you are speaking about, when you cannot express in numbers, your knowledge is of a meagre and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely in your thoughts advanced to the stage of a science, whatever the matter be." This simple statement sums up the aims, objectives and hopefully the achievements of this conference. To discuss and disseminate the current knowledge on non-metallic materials in order that realistic predictions of in-service performance may be made.