Investigations on the initiating processes in radiation-induced ionic polymerization.

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Kyoto University , [Kyoto, Japan
Addition polymerization -- Effect of radiatio
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LC ClassificationsQD381 .S49
The Physical Object
Paginationl v. (various pagings)
ID Numbers
Open LibraryOL5323861M
LC Control Number72176572

In book: Ionizing Radiation Effects and Applications To understand ionizing radiation-induced polymerization, the. The polymerization process was carried out by dissolving two salts of Fe2. In general, the effect of high energy radiation on vinyl monomers in the liquid state is to initiate polymerization by a free radical mechanism.

Inhowever, Davison, Pinner and Worrall 1 polymerized isobutylene with both cobalt 60 gamma and electron beam irradiation to high molecular weight polymers. Since this monomer is known to polymerize only by a cationic mechanism, it was evident that radiation could indeed initiate ionic polymerizations Author: V.

Stannett, A. Deffieux, W. Hsieh, H. Kubota, D.

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Squire. These observations suggest that the ion radicals of monomers play an important role in the initiation process of radiation-induced ionic polymerization, being precursors of the propagating carbanion or carbonium ion.

On the basis of the above electron spin resonance studies, the initiation process is discussed by: 2. RECENT investigations 1–3 on the radiation-induced polymerization of certain monomers have provided evidence for the production of ionic as opposed to radical : T.

Bates. In Ionic Polymerization and Related Processes, internationally recognised academic and industrial researchers discuss and debate the latest developments in the major focus is on cationic polymerizations, but related anionic and controlled radical processes are also discussed.

Details Investigations on the initiating processes in radiation-induced ionic polymerization. FB2

At high conversions the polymer itself becomes activated by the radiation and the monomer is then “homografted” on its own polymer. In the presence of a solvent the polymerization is initiated by radicals resulting from the radiolysis of monomer and solvent.

In such binary mixtures either “sensitization” or “deactivation” may follow from energy transfer by: either of which involves a chain addition process or a step-growth mechanism.

Radiation-induced polymerization, for the most part, proceeds by a chain ad-dition mechanism [1]. In principle, step-growth processes can be triggered by the generation of catalysts resulting from the interaction between radiation and the precursors ofFile Size: KB.

Conventional processes involving radiation initiation may become of practical interest in view of the low cost of radiation as compared with chemical methods. However, the most promising applications are con- Radiation Induced Polymerization cerned with polymerizations conducted in very viscous or semi-solid by: Radical processes initiated by ionizing radiation in PEEK and their macroscopic consequences The precursor initiating the reaction is a cyclohexadienyl radical that theoretically can be generated in PEEK and was the mechanisms of radiation induced processes may be different due to dissimilar access of oxygen molecules and different Cited by: 1.

Dear Colleague, INTECH OPEN ACCESS BOOK has put me in charge to edit a book entitled Ionizing Radiation Effects and Applications. The benefits of ionizing radiations have been largely demonstrate. This absorption spectrum with maxima at, 6hO, and nm is in good agreement with that of the vinylcarbazole cation observed in butylchloride matrix at 77 K.

The ionic polymerization is influenced by cation scavengers, oxygen and kind of solvents. These effects on the polymerization have been by: 4. Investigation in the field of radiation‐induced solid‐state polymerization. XII. liquid‐phase copolymerization proceeds at a higher rate than in the solid phase and probably according to an ionic mechanism.

Abstract by: 1. We use cookies to offer you a better experience, personalize content, tailor advertising, provide social media features, and better understand the use of our services. Radiation emulsion polymerization is a polymerization method in which the polymerization reaction is initiated by the free radicals produced by the radiolysis of water when the emulsion is exposed to high energy ionizing radiation.

4 No extra chemical initiators and heat sources are needed to trigger and control the polymerization : Mozhen Wang, Xuewu Ge, Zhicheng Zhang.

Previously published experimental details of the radiation-induced polymerization of iso-butene, together with new experimental details are reviewed critically in the light of a kinetic scheme. The essential features of this scheme are (i) initiation of polymerization by radiation-produced ions, (ii) propagation of polymer chains by a carbonium ion mechanism, (iii) termination of chains by a.

The radiation-induced ionic polymerization of bulk styrene has been studied under extremely dry conditions. It was found that the rate of propagation increases with more rigorous drying of the. During radiation-induced ionic grafting, the chain propagates without a counter-ion, and therefore the radiation-induced grafting polymerization may be considered free-ion.

An initial event in radiation- induced ionic grafting can be either radical or ionic. The relationship between the numbers of these events depends on the by: The radiation-induced ionic polymerization of bulk styrene has been studied under extremely dry conditions.

best be explained as due to one or more ionic processes, depending on the dryness of. Room temperature ionic liquids (RTILs) have proved over recent years to be useful and unique reaction media for a variety of chemical reactions.

Faster reaction rates and better selectivities are o Cited by: 3. The general kinetics of radiation-induced ionic polymerization are discussed and the effects resulting from impurity termination are analyzed quantitatively. A method is described for the calculation of the propagation rate constants by combining measurements of polymerization Cited by: Polymerization induced by ionizing radiation at low temperatures.

Evidence for the simultaneous existence of ionic and free‐radical mechanisms in the polymerization of styrene and 2,4‐dimethylstyreneCited by: Ionic polymerization is a chain-growth polymerization in which active centers are ions or ion pairs.

It can be considered as an alternative to radical polymerization, and may refer to anionic polymerization or cationic polymerization. As with radical polymerization, reactions are initiated by a. Chapter 8 Ionic Chain Polymerization The carbon–carbon double bond can be polymerized either by free radical or ionic methods.

The difference arises because the p-bond of a vinyl monomer can respond appropriately to the initiator species by either homolytic or heterolytic bond breakage as shown in Eq.

CC CC CC ðÞAuthor: Wei-Fang Su. consultants meeting on Advances in Radiation Chemistry of Polymers held at the University of Notre Dame, USA in September was the first in this series. The new developments concerning polymer processing were reported and the status of the technology was reviewed during the Size: 1MB.

Controlling of Degradation Effects in Radiation Processing of Polymers, covering the years This technical publication compiles the most important results and achievements of the participating centers and laboratories during the course of the said CRP.

It has been prepared to give.

Description Investigations on the initiating processes in radiation-induced ionic polymerization. FB2

Polymers, an international, peer-reviewed Open Access journal. Dear Colleagues, We are very fortunate to have the opportunity to edit a Special Issue named “Radiation Polymers” for publication in hope to bring an inspiring view on current trends and research focus on the radiation effect and radiation technology in the polymer sciences through this Special Issue.

Analysis of radiation-induced ionic polymerization Degradation of polymer Data for the degradation of polyisobutene at C are shown in figure 2. The results for pure polyisobutene follow the relation: 1w= +1 x wher r s te doe i MrdsM' -+1F3xO- (2) where r is the dose in Mrads, eM, M, are the viscosity-average molecular weights.

Irradiation polymerization and synthesis provides an additive-free method of inducing polymerization and modifying already existing polymers with new properties tuned to specific applications. I continue to see an expansion in the number of fields in which heavy ion- and electron-beam irradiations are successfully utilized.

Photoinitiated Cross-Linking Polymerization of Monomer Blends Christian Decker Chapter 8, DOI: /bkch Publication Date (Print): March 3, Monomer Molecule Anionic Polymerization Cationic Polymerization Ionic Polymerization Glycol Dimethyl Ether These keywords were added by machine and not by the authors.

This process is experimental and the keywords may be updated as the learning algorithm improves. Mechanisms for Initiating Polymerization by Stable Organic Cations A. LEDWITH Chap DOI: /bach Publication Date (Print): June 1, @article{osti_, title = {Mechanism of radiational ionic graft polymerization}, author = {Kabanov, V Y and Aliev, R E and Kudryavtsev, V N and Sidorova, L P and Spitsyn, V I}, abstractNote = {The present paper discusses the mechanism of initiation in radiational ionic graft polymerization, with special attention given to the heterogeneous aspects of the grafting process.A Novel Mechanism of Ionic Polymerization SHIRO KOBAYASHI Chap DOI: /bkch Publication Date (Print): Aug