Download or read book Stabilization and Modification of Cellulose Diacetate written by F. Niyazi and published by . This book was released on 2009 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Stabilization and Modification of Cellulose Diacetate written by Farukh Fatehovich Niyazi and published by . This book was released on 2008-10 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cellulose and its derivatives -- cellulose acetate -- are renewed polymers, that, together with the whole complex of valuable and indispensable properties, defines continuous growth of their production. Acetate fibres differ from cellulose fibres in light and thermooxidative stability, as the presence of ester groups decreases stability of molecular structure, owing to which destructive processes begin at much lower temperatures and weak energy effects. Since macromolecules of cellulose acetate are constructed on the basis of cellulose then mechanism of photodestruction of these polymers may be considered as general. The most important energetic factor, which photodestruction of cellulose and its derivatives depend on, is intensity of irradiation and wave length. Destruction of cellulose and its derivatives under atmospheric conditions, proceeding as a result of photochemical reaction, on the whole takes place under the action of ultraviolet rays with ?=200-360 nm. Since cellulose contains three types of chromophore groups -- hydroxyl, acetate and semiacetate and also aldehyde -- then it is considered that light absorption in the region of 250-300 nm is caused just by them. At the same time some authors, bringing the possibility of light absorption by acetal chromophore in question, have put forward the supposition that photochemically active centres in cellulose materials, containing carboxyl and hydroxyl groups, may be molecular complexes between these groups, connected by the system of hydrogen bounds with definite energy of interaction. Disproportion of intermolecular bonds, providing fixation of excited state in cellulose matrix takes place in such complexes at their excitation. Thus, there are many different hypotheses, often contradicting each other, about the effect of chromophore groups on light absorption by cellulose. There are many data about the nature of free-radical particles, being formed at irradiation of cellulose by ultraviolet light. Since, being formed products of phototransformation are highly mobile and easily undergo further transformations, method of electron-paramagnetic resonance (ESP) is one of the most effective for these particles identification. Critical analysis of a great number of works on EPR spectra interpretation is quite fully given in surveys. More than 20 different radicals are being formed at ultraviolet irradiation as a result of break of practically all bonds C-C; C-H; C-O. Main types of macroradicals, with indication of atom and groups of atoms after removal of which these macroradicals are formed, are presented in scheme 1. of this book.

Download or read book Photodegradation and Light Stabilization of Heterochain Polymers written by Niyazi and published by CRC Press. This book was released on 2006-11-14 with total page 195 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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).

Download or read book Photochemical Reactions in Heterochain Polymers written by F. Niyazi and published by Nova Publishers. This book was released on 2008 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photochemical reactions are the main class of chemical processes. These processes provide for life on Earth, since due to photochemical processes, plants absorb carbon oxide from the atmosphere changing them into the "meal" for all creatures on Earth. Together with "good" photochemical processes there are some "bad" as well. This book is about photodestruction and light stabilisation and is devoted to these processes. For example, the heterochain polymers. They are the main class of large-tonnage polymers, which are used for manning a great variety of polymer and composite materials (including nanocomposites).

Download or read book Photodegradation and Light Stabilization of Heterochain Polymers written by Niyazi and published by CRC Press. This book was released on 2019-12-02 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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).

Download or read book Chemical Modification of Lignocellulosic Materials written by DavidN.-S. Hon and published by Routledge. This book was released on 2017-09-29 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume emphasizes the growing need for wood products with advanced engineering properties. It details the fundamental principles of cellulose technology and presents current techniques to modifying the basic chemistry of lignocellulosic materials. The work: discusses the cost-efficient use of cellulose derivatives in a variety of commodities; highlights the chemical modification of wood by methods such as etherification, esterification and thermoplasticization; considers recent progress in the lignocellulosic liquefaction of wood; and more.

Download or read book Cellulose Acetates Properties and Applications written by Paul Rustemeyer and published by Wiley-VCH. This book was released on 2004-08-13 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: To mark the 100th anniversary of cellulose diacetate in 2004, academic expertise on the physical and chemical properties of cellulose acetates (CA) is combined in this volume with industrial knowledge on technology and product properties.

Download or read book Technology of Cellulose Esters written by Edward Chauncey Worden and published by . This book was released on 1921 with total page 940 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Improving the Hydrolytic Stability of the Forward Osmosis Cellulose Acetate Membrane Via Polydopamine Surface Modification written by Justin Durelli and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Technology of Cellulose Esters written by Edward Chauncey Worden and published by . This book was released on 1921 with total page 640 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Biodegradable Polyesters written by Stoyko Fakirov and published by John Wiley & Sons. This book was released on 2015-04-06 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: Collating otherwise hard-to-get and recently acquired knowledge in one work, this is a comprehensive reference on the synthesis, properties, characterization, and applications of this eco-friendly class of plastics. A group of internationally renowned researchers offer their first-hand experience and knowledge, dealing exclusively with those biodegradable polyesters that have become increasingly important over the past two decades due to environmental concerns on the one hand and newly-devised applications in the biomedical field on the other. The result is an unparalleled overview for the industrial chemist and materials scientist, as well as for developers and researchers in industry and academia alike.

Download or read book Cellulose and Cellulose Derivatives written by Kenji Kamide and published by Elsevier. This book was released on 2005-08-31 with total page 653 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many highly acclaimed and authoritative books on polymer science tend to focus on synthetic polymers. Cellulose and Cellulose Derivatives is the first authoritative book on the subject. It examines recent developments, with particular reference to cellulose (in aqueous alkali) and cellulose acetate. Packed with examples, the author takes an in-depth look at the topic, using the most reliable experimental data available. A comprehensive approach to the fundamental principles of cellulose and its derivatives in solution makes Cellulose and Cellulose Derivatives ideal reading for novices as well as experienced cellulose scientists.* Outlines the theoretical fundamentals of cellulose and cellulose derivatives* Presents comprehensive and reliable experimental results in figures and tables * Highly illustrated and easy to read

Download or read book Saline Water Conversion Report written by United States. Office of Saline Water and published by . This book was released on 1965 with total page 1152 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Saline Water Conversion Report for written by United States. Office of Saline Water and published by . This book was released on 1966 with total page 1342 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Cellulose Nanocrystals written by Vimal Katiyar and published by Walter de Gruyter GmbH & Co KG. This book was released on 2020-10-12 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cellulose nanocrystals are being used more frequently as processing and nanofabrication techniques have advanced considerably. Cellulose Nanocrystals includes topics including Extraction and Fabrication Methodologies, Scale-Up Strategies and Life Cycle Assessment, Surface Modification Strategies, Nanocomposites, and Characterization and Testing Protocols. This book will appeal to physical, chemical and biological scientists as well as engineers.

Download or read book Biofunctional Membranes written by D.A. Butterfield and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 289 pages. Available in PDF, EPUB and Kindle. Book excerpt: ''Interesting with many useful ideas and references. It covers a broad range and it is a good introduction to this field.'' ---Analyst

Download or read book Polymer Modification written by John Meister and published by CRC Press. This book was released on 2000-07-25 with total page 936 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Describes new modification methods and applications for natural, synthetic, thermoplastic, and thermoset polymers that result from economic forces, commercial processes, and the latest research and development. Features chemical and physical technologies such as sulfonation, alkylation, acid/base hydrolysis, hydrogenation, stress orienting, anneal