Radiochemical photochemical oxidation

The radiochemical oxidation of PS in a chloroform solution is accompanied by its destruction and formation of products of styrene oxidation, namely, benzaldehyde and styrene oxide [136]. The radiochemical yield of these products was equal to the radiochemical yield of PS macromolecule cleavages. Butyagin [137] analyzed the products of decomposition of the peroxyl radicals of PS and polyvinyIcyclohexane. Alkyl macroradicals were produced mechano- or photochemically, volatile products were evaporated in vacuum, and alkyl radicals were converted into peroxyl radicals using labeled lsO. Peroxyl radicals were then... 

Aging can be defined as a slow and irreversible (in use conditions) variation of a material s structure, morphology and/or composition, leading to a deleterious change of use properties. The cause of this change can be the proper material s instability in use conditions or its interaction with the environment (oxidation, hydrolysis, photochemical, radiochemical, or biochemical reactions, etc.). 

As is described in more detail in subsequent sections, it is well established that iron (III) porphyrins can be reduced by photochemical, electrochemical, and radiochemical methods in organic or aqueous solutions to give Fe and Fe complexes.Recently, it has also been shown that such reactions lead to the formation of complexes with the iron in the zero oxidation state. Such Fe° porphyrins are, for example, formed electrochemically when Fe porphyrins ([PFe ]+) are reduced in three successive steps in DMF in the presence of a weak Bronsted acid as co-catalyst to yield the iron (II) porphyrin ([PFe ]), the iron(I) porphyrin ([PFe ] ) and the iron(O) porphyrin 503-506 jj-on(0) porphyrins are... 

Shape of oxidation kinetic curves in the case of initiation (a) at constant rate (case of radiochemical ageing) thermal ageing) and (c) by unimolecular Per decomposition (case of many photochemical ageings). 

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