Hydroperoxide groups photodecomposition

UV wavelengths which damage certain polymers. The absorbed photons raise electrons to an excited state and cause bond dissociation reactions. An example is the photodecomposition of hydroperoxide groups introduced during melt processing. 

Acetophenone end-groups, which develop as a result of thermal and/or photodecomposition of hydroperoxide groups (cf. section 3.11.1.6) ... 

In order for Eq. (33) to be in agreement with the experimental result, it must be admitted that the second term in the right member is negligible with respect to the first therefore, under the experimental conditions adopted, hydroperoxides disappear almost exclusively due to photodecomposition (26). The decrease in decomposition rate in the presence of oxygen is obviously due to the well-known reaction of alkyl radicals with oxygen, which leads to the additional formation of hydroperoxide groups [reactions (3) and (4)] hence the rate of photochemical decomposition apparently decreases. 

Photodecomposition of polymer hydroperoxides yields polymer oxy radicals (PO ), and finally carbonyl and hydroxide groups ... 

Photodecomposition of hydroperoxide (OOH) groups subsequently gives end-hydroxyl (OH) and end-formyl(aldehyde) (—C ) chains ... 

The chain scission reaction may occur by thermal and/or photodecomposition of the hydroperoxide (OOH) group [785] ... 

We review in this chapter the nature of the photodecomposition pathways of several of the major products of atmospheric oxidation of the hydrocarbons, namely, the acyclic aldehydes in section IX-B the aldehydes containing additional functional groups in section IX-C the acyclic ketones in section IX-D the cyclic ketones in section IX-E the ketones containing additional functional groups in section IX-F the acyl halides and carbonyl halides in section IX-G nitrous acid, the alkyl nitrites, the nitroalkanes, and the nitroso-compounds in section IX-H nitric acid and the alkyl nitrates in section IX-I the peroxyacyl nitrates in section IX-J the alkyl hydroperoxides in section IX-K and some oxygenates derived from the aromatic hydrocarbons in section IX-L. 

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