Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Polymer radiation damage

Of some interest is also co-crosslinking of various synthetic polymers, their blends with natural ones as well as compositions with inert or active fillers numerous patents are devoted to these materials (for example, Refs. [87, 88]). Low doses of crosslinking allow to introduce various physiologically active additives into SAH without any danger of radiation damage. This possibility is particularly attractive for the technology of SAH. [Pg.109]

As already indicated in Scheme 2.12, XRF is profitably used for general screening of polymer formulations on inorganic components, before and after extraction. In the case of several PVC blends, such screening has indicated the presence of Cl, Ca, Ti, Cr, Fe, Zn, Mo, Cd, Sn, Sb and Pb [255]. It is well known that X-ray radiation may cause radiation damage, such as coloration of PVC samples during XRF analysis. [Pg.635]

Polymers with chromophores exhibiting mt transitions (e.g., C=0) exhibit weaker UV-absorption and these groups together with unsaturated carbon-carbon bonds which develop during radiation damage can be detected by electronic absorption spectroscopy. [Pg.28]

Electron irradiation causes chain scission and crosslinking in polymers. Both of these phenomena directly affect the glass transition temperature (Tg) of the materials. Thermomechanical (TMA) and dynamic-mechanical analysis (DMA) provide information about the Tg region and its changes due to radiation damage. Therefore, DMA and TMA were performed on all irradiated materials. [Pg.228]

Although TEM-HREM is a more useful technique as can reveal a picture of the atoms in the materials, however this picture is difficult to interpret. On the other hand, radiation damage from the electron beam is an issue (in HREM observations), as long periods of TEM observation (> 1 min) usually can alter/damage seriously the stmcture of many industrial applications materials like organic chemical compounds, zeolites, polymers, etc. [Pg.170]

Sauvaigo S, Petec-Calin C, Caillat S, Odin F, Cadet J (2002) Comet assay couple to repair enzymes for the detection of oxidative damage to DNA induced by low doses of y-radiation use of YOYO-1, low-background slides, and optimized electrophoresis conditions. Anal Biochem 303 107-109 Schnabel W (1986) Pulse radiolysis studies concerning oxidative degradation processes in linear polymers. Radiat Phys Chem 28 303-313... [Pg.503]

XPS of Polymer Surfaces Analytical Applications Radiation Damage Surface Modified Electrodes Interfacial Chemistry and Adhesion Surface Chemistry and Catalysis Mineralogy and Geochemistry Microelectronics Processing... [Pg.145]

Pulse radiolysis experiments on solid polymers have provided new insight into the mechanism of radiation damage of polymers. Recent studies on some practically important polymers clarified the pathways of transfer of radiation-induced excitation energy from polymer matrix to additives thus the roles of additives in the radiation resistance or sensitivities of polymers are understood in terms of elementary energy transfer processes. The usefulness of this method is verified not only in the basic science but also in the field of application. [Pg.77]

It is useful to discuss these results within a model of the radiation-damaged polymer. Our original report (.10) on x-irradiation of PTFE concluded that the damaged material was a highly cross-linked and branched network. The new observations, reported here, permit further elaboration of the model. [Pg.231]

Ceramic membranes are quite important since microporous ceramics are the principal barrier in UFe separation. Similar devices are used for microfiltration membranes and to a lesser extent for ultrafiltration. Homogeneous films are transformed into microporous devices by irradiation followed by selective leaching of the radiation damaged tracks, by stretching (Cortex is one welldmown example), or by electrochemical attack on aluminum. A few membranes are made by selective leaching of one component from a solid, as in membranes derived from glass or by selective extraction of polymer blends. [Pg.1784]

Radiation induced changes in the electronic structure of all samples were evident as changes in energy loss spectrum with increased exposure to the electron beam. The spectrum of radiation induced chromophores could thus be studied (1 ). Spectra recorded at the earliest exposure times compared favorably with optical results and are believed to contain primarily intrinsic electronic excitations (1, 2, 4). An analysis of these intrinsic spectra is the subject of the bulk of this paper. The spectra of radiation damaged polymers are described briefly after the intrinsic excitations are discussed. [Pg.35]


See other pages where Polymer radiation damage is mentioned: [Pg.53]    [Pg.47]    [Pg.53]    [Pg.47]    [Pg.172]    [Pg.321]    [Pg.257]    [Pg.37]    [Pg.374]    [Pg.498]    [Pg.500]    [Pg.488]    [Pg.366]    [Pg.367]    [Pg.371]    [Pg.374]    [Pg.376]    [Pg.662]    [Pg.18]    [Pg.35]    [Pg.90]    [Pg.94]    [Pg.250]    [Pg.23]    [Pg.94]    [Pg.109]    [Pg.89]    [Pg.104]    [Pg.24]    [Pg.142]    [Pg.131]    [Pg.321]    [Pg.176]    [Pg.342]    [Pg.197]    [Pg.133]    [Pg.59]    [Pg.450]    [Pg.108]    [Pg.434]    [Pg.327]    [Pg.172]   
See also in sourсe #XX -- [ Pg.196 ]




SEARCH



Polymer damage

Radiation damage

© 2024 chempedia.info