Science

Thermal Degradation of Polymeric Materials

Author: Krzysztof Pielichowski

Publisher: iSmithers Rapra Publishing

ISBN:

Category: Science

Page: 306

View: 769

Understanding the thermal degradation of polymers is of paramount importance for developing a rational technology of polymer processing and higher-temperature applications. Controlling degradation requires understanding of many different phenomena, including chemical mechanisms, the influence of polymer morphology, the complexities of oxidation chemistry, and the effects of stabilisers, fillers and other additives. This book offers a wealth of information for polymer researchers and processors requiring an understanding of the implications of thermal degradation on material and product performance.
Technology & Engineering

Environmental Degradation of Advanced and Traditional Engineering Materials

Author: Lloyd H. Hihara

Publisher: CRC Press

ISBN:

Category: Technology & Engineering

Page: 719

View: 396

One of the main, ongoing challenges for any engineering enterprise is that systems are built of materials subject to environmental degradation. Whether working with an airframe, integrated circuit, bridge, prosthetic device, or implantable drug-delivery system, understanding the chemical stability of materials remains a key element in determining their useful life. Environmental Degradation of Advanced and Traditional Engineering Materials is a monumental work for the field, providing comprehensive coverage of the environmental impacts on the full breadth of materials used for engineering infrastructure, buildings, machines, and components. The book discusses fundamental degradation processes and presents examples of degradation under various environmental conditions. Each chapter presents the basic properties of the class of material, followed by detailed characteristics of degradation, guidelines on how to protect against corrosion, and a description of testing procedures. A complete, self-contained industrial reference guide, this valuable resource is designed for students and professionals interested in the development of deterioration-resistant technological systems constructed with metallurgical, polymeric, ceramic, and natural materials.
Technology & Engineering

The Concept of Micellar-Sponge Nanophases in Chemical Physics of Polymers

Author: Yuri Arsenovich Mikheev

Publisher: CRC Press

ISBN:

Category: Technology & Engineering

Page: 450

View: 169

The monograph is intended for elucidation of the novel trend in chemical physics regarding the polymer non-crystalline phase. It stresses the physical phenomena affecting the kinetics and mechanism of chemical reactions proceeding in the non-crystalline polymer matrix (NCPM). NCPM is depicted in terms of a supramolecular (carcass-micellar) model. The model is thought to reflect heterophase packing of polymeric chains, which co-operate as a molecular-chain sponge. The NCPM model presented is proved for adequate description of principal structure-physical phenomena to elaborate the scheme of structural-kinetic modeling of chemical reactions in bulky polymers. Structure-physical phenomena elucidated in the monograph are: - peculiarities of polymer plasticization and polymer blending with liquids; - structural and thermodynamic aspects of sorption of low molecular species; - properties of ESR (spin) probes and optical (molecular) probes; - features of water absorbed by polymers; - mechanical and thermal effects generated by the molecular-chain sponge; - supramolecular aspects of NCPM chemical physics. This monograph includes the structural-kinetic modeling of complex polymer chemical reactions. It deals with the problem of mechanism and kinetics of free radical chain reactions using thermal and photochemical model reactions of dibenzoyl peroxide with glassy-like polymers (cellulose triacetate, polycarbonate, polystyrene, polyamide PA-548), viscoelastic polymers (atactic polypropylene, polyamide PA-548, polyethylene, polyisobutylene, melted poly(ethylene oxide), and isotactic polypropylene. In all cases, the supramolecular heterophase mechanism of the processes, which was unknown for homogeneous systems, was proved. Furthermore, heterophase mechanisms of photochemical reaction between naphthalene and cellulose triacetate and photolysis of poly(methyl methacrylate) proceeding as a photochain reaction are indicated.
Technology & Engineering

Handbook of Polymer Degradation

Author: S. Halim Hamid

Publisher: CRC Press

ISBN:

Category: Technology & Engineering

Page: 800

View: 949

"Covers recent advances in polymer degradation and stabilization. Focuses on the basics of photo- and bio-degradability. Delineates special and general environmental parameters such as solar irradiation, temperature, and agrochemical exposure. Surveys plastic waste disposal strategies such as recycling, incineration, chemical recovery by pyrolysis,
Technology & Engineering

Photodegradation and Light Stabilization of Heterochain Polymers

Author: Niyazi

Publisher: CRC Press

ISBN:

Category: Technology & Engineering

Page: 192

View: 908

Photodegradation and light stabilization are very important aspects of polymer aging. Polymer degradation includes different types of processes: thermodegradation, oxidation, acting of ozone, photodegradation, radiation, hydrolysis, mechanical degradation, and biodegradation. It is very important to know the mechanism of polymer degradation in order to select stabilizers against the degradation. This volume presents the analysis of achievements in the field of photodegradation of polymers. It includes, first of all, data of Russian investigators who have decisively contributed in the development of this field of knowledge (the schools headed by academicians V.V. Korshak, N.M. Emanuel, N.S. Enikolopov, A.A. Berlin, and many others).
Science

Polymer Degradation and Stabilisation

Author: Norman Grassie

Publisher: CUP Archive

ISBN:

Category: Science

Page: 232

View: 636

The study of polymer degradation and stabilisation is of considerable practical importance as the industrial uses of polymeric materials continue to expand. In this book, the authors lucidly relate technological phenomena to the chemistry and physics of degradation and stabilisation processes. Degradation embraces a variety of technologically important phenomena ranging from relatively low temperature processes such as 'weathering' of plastics, 'fatigue' of rubbers through the processing of polymers in shearing mixers to very high temperature processes such as flammability and ablation. All these technological phenomena have in common certain basic chemical reactions. Thus 'weathering' has its roots in photo-oxidation, 'fatigue' and melt-degradation in mechano-oxidation and flammability, and ablation in ablation in pyrolysis and vapour phase oxidation.