Big Chemical Encyclopedia

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

Articles Figures Tables About

Radicals formation during irradiation

Based on these results we used electron spin resonance (ESR) spectroscopy to study the formation and stability of free radicals in paper samples after irradiation. Free radicals formed during irradiation but disappeared during storage. Figure 5 shows the... [Pg.152]

When the irradiation was carried out with light including shorter wavelengths, the carbonyl groups also contributed to radical formation by the Norrish type-I reaction (75). This was confirmed by acyl radical formation during the warming-up process as in the case of polyethylene... [Pg.157]

A very important process occurring during irradiation is the formation of free radicals that leads to other changes, such as cross-linking, polymerization reactions, and grafting. [Pg.105]

Thus, electron magnetic resonance is an important tool in the detection and structure analysis of radicals in polymeric systems (during formation, oxidation, irradiation, pyrolysis and mechanical rupture). From these patterns the chemical structure of the radicals may be derived. For the study of short-lived radicals flow systems have been developed. Free radicals in glassy polymers, however, may have an extremely long life. [Pg.380]

Free radicals are generated at the wood surface during irradiation. The rate of free radical formation is enhanced when moisture content increases from 0 to 6.3%. Electron spin resonance and UV studies on the behavior of free radicals generated and their interactions with oxygen molecules to form hydroperoxides revealed that free radicals and singlet oxygen play important roles in discoloration and deterioration reactions of wood surfaces. [Pg.446]

ESR (or electron paramagnetic resonance, EPR), has been used for the study of free radicals in polymers during the polymerization process or for the measurement of free radical formation upon the irradiation of the polymer with UV light or gamma rays. X-ray diffraction has been used for the determination of spatial arrangement of the atoms in a polymer and for the measurement of the degree of crystallinity. [Pg.27]

See other pages where Radicals formation during irradiation is mentioned: [Pg.246]    [Pg.32]    [Pg.758]    [Pg.174]    [Pg.246]    [Pg.32]    [Pg.758]    [Pg.174]    [Pg.9]    [Pg.221]    [Pg.245]    [Pg.148]    [Pg.711]    [Pg.198]    [Pg.496]    [Pg.34]    [Pg.119]    [Pg.331]    [Pg.548]    [Pg.70]    [Pg.319]    [Pg.88]    [Pg.879]    [Pg.168]    [Pg.196]    [Pg.69]    [Pg.755]    [Pg.229]    [Pg.243]    [Pg.262]    [Pg.337]    [Pg.154]    [Pg.173]    [Pg.315]    [Pg.344]    [Pg.601]    [Pg.60]    [Pg.212]    [Pg.254]    [Pg.63]    [Pg.296]    [Pg.57]    [Pg.194]    [Pg.434]    [Pg.260]    [Pg.434]   
See also in sourсe #XX -- [ Pg.246 ]



SEARCH



During irradiation

Formate radicals

Radical formation

© 2024 chempedia.info