Polymers, Natural Organic

Manufactured fibers produced from natural organic polymers are either regenerated or derivative. A regenerated fiber is one which is formed when a natural polymer or its chemical derivative is dissolved and extmded as a continuous filament, and the chemical nature of the natural polymer is either retained or regenerated after the fiber-formation process. A derivative fiber is one which is formed when a chemical derivative of the natural polymer is prepared, dissolved, and extmded as a continuous filament, and the chemical nature of the derivative is retained after the fiber-formation process. [Pg.439]

S.C. Moldoveanu, Analytical Pyrolysis of Natural Organic Polymers, Elsevier, Amsterdam (1998). [Pg.283]

Natural nuclear reactors, 17 589 25 397 Natural organic polymers, manufactured fibers produced from, 24 616 Natural photocatalytic processes, in the environment, 19 100-101 Natural plant growth regulators, 13 22-28 Natural polymer hollow fibers, 16 23... [Pg.613]

Class Water-soluble synthetic and natural organic polymers, which increase the viscosity of the mixing... [Pg.319]

Class A. Water-soluble synthetic and natural organic polymers, which increase the viscosity of the mixing water. They include cellulose ethers, pregelatinized starches, polyethylene oxides, alginates, carrageenans, polyacrylamide, carboxyvinyl polymers and polyvinyl alcohol. [Pg.228]

Volume 20 Analytical Pyrolysis and Natural Organic Polymers... [Pg.401]

Analytical Pyrolysis Applied to Natural Organic Polymers. [Pg.5]

The usefulness of analytical pyrolysis in polymer characterization, identification, or quantitation has long been demonstrated. The first application of analytical pyrolysis can be considered the discovery in 1860 of the structure of natural rubber as being polyisoprene [10]. This was done by the identification of isoprene as the main pyrolysis product of rubber. Natural organic polymers and their composite materials such as wood, peat, soils, bacteria, animal cells, etc. are good candidates for analysis using a pyrolytic step. [Pg.5]

In principle, there is no difference between the analytical pyrolysis of natural organic polymers and that of other samples. Although the basics are the same, there are... [Pg.5]

The first part of this book, dedicated to the description of the analytical pyrolysis methodology, will not be specific to natural organic polymers. The second and the third part, however, will cover only applications specific to natural organic polymers, chemically modified natural organic polymers, and their composite materials. [Pg.6]

Eliminations and other reactions do not necessarily take place only on the polymeric chain or only on the side groups. Combined reactions may take place, either with a cyclic transition state or with free radical formation. The free radicals formed during polymeric chain scission or during the side chain reactions can certainly interact with any other part of the molecule. Particularly in the case of natural organic polymers, the products of pyrolysis and the reactions that occur can be of extreme diversity. A common result in the pyrolysis of polymers is, for example, the carbonization. The carbonization is the result of a sequence of reactions of different types. This type of process occurs frequently, mainly for natural polymers. An example of combined reactions is shown below for an idealized structure of pectin. Only three units of monosaccharide are shown for idealized pectin, two of galacturonic acid and one of methylated galacturonic acid ... [Pg.25]

The study of natural organic polymers is an extremely complex and difficult task. [Pg.502]

The second part presents the results of pyrolysis for individual natural organic polymers and some chemically modified natural organic polymers. It describes the main pyrolysis products of these compounds as well as the proposed pyrolysis mechanisms. This part is intended to be the core of the book, and it is an attempt to capture as much as possible from the chemistry of the pyrolytic process of natural organic polymers. The third part of the book is more concise and describes some of the practical applications of analytical pyrolysis on natural organic polymers and their composite materials. These applications are related to analysis, characterization, or comparison of complex samples. However, it includes only examples on different subjects, and it is not a comprehensive presentation. A variety of details on specific applications are described in the original papers published in dedicated journals such as the Journal of Analytical and Applied Pyrolysis. ... [Pg.502]

The present book is a follow-up of a previous one with the title Analytical Pyrolysis of Natural Organic Polymers published by Elsevier as vol. 20 in the series Techniques and Instrumentation in Analytical Chemistry. In addition to the discussion on pyrolysis of various natural polymers, the previous book contains information on chemically modified celluloses, modified starches, etc. For this reason, the present book does not include synthetically modified natural polymers. Information on the pyrolysis process and pyrolytic techniques in general also can be found in the book on natural polymers. [Pg.1]

The classification of polymers previously described has been used in this book for the discussion of pyrolysis results. An important class of polymers that is not discussed here is that of chemically modified natural polymers (or semisynthetic polymers). Examples of such polymers are the modified celluloses (carboxymethyl cellulose, ethyl cellulose, etc ), modified starches, casein plastics (Galalith), etc. These types of compounds were discussed in the book on pyrolysis of natural organic polymers [2]. [Pg.20]

Natural organic polymers - such as structural proteins (ceratin, collagen),... [Pg.107]

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