Science

Stabilization of Polymeric Materials

Author: Hans Zweifel

Publisher: Springer Science & Business Media

ISBN:

Category: Science

Page: 219

View: 293

Plastics are used worldwide in everyday life, e.g. as food packaging, electronics, construction, automotive parts, and household appliances. To produce these products with the desired service lifetimes the use of suitable stabilizers is necessary. This book provides a concise and comprehensive overview of the basic mechanisms of plastic degradation processes caused by heat and light. At its core is a detailed description of the stabilization of different polymers, including an explanation of stabilization mechanisms and the influence of commonly used additives such as fillers, flame retardents and pigments on the stability of plastic. Every polymer scientist, material technologist, or application engineer dealing with the design of the properties of plastics will benefit from this new overview.
Technology & Engineering

Aging and Stabilization of Polymers

Author: M. B. Neiman

Publisher: Springer Science & Business Media

ISBN:

Category: Technology & Engineering

Page: 366

View: 535

The need for a broad development of the production of polymer ma terials has become evident. All these materials are subject to various types of aging (destruction); hence, stabilizers which permit the stor age, reprocessing, and use of polymer materials without any appreci able change in their properties must be introduced into them. In recent years, this problem of stabilizing polymers has attracted the attention of many scientists and technologists, both in the USSR and abroad. The scientific basis of the foreign studies will be found in a number of theo retical premises, but chiefly the theory of chain reactions with un branched chains. In the Soviet Union, the concepts of Academician N. N. Semenov on chain reactions with degenerate branches have become the starting point of theoretical studies of the stabilization and destruction of polymers. Soviet scientists have developed a theory of critical concentrations of antioxidants and have shown that the processes of stabilization have a very complex chemical character. The nature of the polymers them selves greatly affects these processes and consequently, different stabil izers are required for polymers of different structures. In addition, it has been shown that the antioxidants used thus far can not only cause chain termination, but can also initiate oxidation and give rise to de generate branches.
Technology & Engineering

Resistance and Stability of Polymers

Author: Gottfried Ehrenstein

Publisher: Carl Hanser Verlag GmbH Co KG

ISBN:

Category: Technology & Engineering

Page: 1460

View: 775

The stability and resistance of polymeric materials determine whether they can be utilized in a given application. Authoritative and reliable material information is needed during the material selection process and this information must consider the influences of material manufacturing, compounding and stabilization, processing, part design, use and subsequent disposal/recycling. This book is based on the review of more than 1200 literature sources and represents a comprehensive overview of the current know-how regarding the stability and resistance of thermoplastics, thermosets, elastomers as well as the most commonly used reinforcementsand additives. Extensive tables document material resistance to given media, facilitating appropriate material selection or stabilization for a given application. Contents Volume 1: Principles of Aging Testing Methods Stabilization Influence of Processing and Use Resistance to Thermal and Thermal-Oxidative Loads, Weathering, Chemicals, Ionizing Radiation, Microorganisms, Biological Influences, and Mechanical Loads Creep and Fatigue of Reinforced Polymers Contents Volume 2: Chemical Resistance Tables White Lists of Media Influence (According to DIBt) References Index
Science

Antioxidative Stabilization Of Polymers

Author: Y A Shlyapnikov

Publisher: CRC Press

ISBN:

Category: Science

Page: 256

View: 713

Polymers play a vital role in manufacturing processes of many kinds, and the development of new polymeric materials is of increasing importance in the field of materials science. Because of this, there is a need to understand why the properties of polymers change, what can be done to avoid degradation and failure, and how performance can be maintained over a much longer lifespan. The authors deal firstly with the process of degradation through oxidation, and then explain how the addition of various antioxidants can inhibit or retard this process. They present a unique discussion of the physico-chemical aspects, particularly the chemical kinetics of antioxidant action and of branched chain reaction kinetics, and the theory of critical phenomena inhibited oxidation. The last part of the book offers practical advice on methods of oxidation investigation, on selection of appropriate antixodants, and on the basic principles of performance prognosis. The book also includes a unique coverage of the regularities of additive solubility.
Science

Photostabilization of Polymers

Author: J.F. Rabek

Publisher: Springer Science & Business Media

ISBN:

Category: Science

Page: 596

View: 838

During the last two decades, the production of polymers and plastics has been increasing rapidly. In spite of developing new polymers and polymeric materials, only 40-60 are used commercially on a large scale. It has been estimated that half of the annual production of polymers is employed outdoors. Increasing the stability of polymers and plastics towards heat, light, atmospheric oxygen and other environmental agents and weathering conditions has always been a very important problem. The photochemical instability of most of polymers limits them to outdoor application, where they are photo degraded fast over periods ranging from months to a few years. To the despair of technologists and consumers alike, photodegrada tion and environmental ageing of polymers occur much faster than can be expected from knowledge collected in laboratories. In many cases, improved methods of preparation and purification of both monomers and polymers yield products of better quality and higher resistance to heat and light. However, without stabilization of polymers by applica tion of antioxidants (to decrease thermal oxidative degradation) and photostabilizers (to decrease photo-oxidative degradation) it would be impossible to employ polymers and plastics in everyday use.
Technology & Engineering

The Structural Stabilization of Polymers: Fractal Models

Author: Kozlov

Publisher: CRC Press

ISBN:

Category: Technology & Engineering

Page: 345

View: 897

This monograph deals with the structural aspects of transport processes of gases, physical ageing and thermo-oxidative degradation of polymers in detail. Fractal analysis, cluster models of the polymer structureas amorphous state as well as irreversible aggregation models are used as main structural models. It is shown that the polymer structure
Technology & Engineering

Thermal Stability of Engineering Heterochain Thermoresistant Polymers

Author: Kalugina

Publisher: CRC Press

ISBN:

Category: Technology & Engineering

Page: 279

View: 558

This book presents investigation results of thermal transformations in thermoresistant polymers: polysulfones, polyester-imides, aliphatic-aromatic polyimides and polyamides, liquid-crystal aromatic co-polyesters, polyphenylquinoxalines at temperatures of materials and articles processing and operation. An important result of investigations is the determination of thermooxidative degradation regularities for aliphatic-aromatic heterochain polymers and description of the degradation mechanism. The applied aspect of this work is the approach to stabilization of thermoresistant polymers and composite materials derived from them using additives and analysis of the mechanism of high-temperature inhibited oxidation. The book presents results which have been obtained through many years of research until recently, mostly obtained by scientists of G.S. Petrov Research Institute of Polymeric Materials (Moscow, Russia) – one of the leading Institutes in this branch - which have not been available in international scientific publications before.