Sensitized photoreactions of polymers in solution

In many cases a chemical compound may, depending on the conditions of the photochemical reaction, behave either as a photo-initiator or as a photosensitizer. Benzophenone is a typical example. For this reason some authors do not distinguish between these two classes of compounds, assuming that their positive influence on the changes of the rate of photochemical reactions represents the sensitization of these reactions. 

In both cases the degradation and photo-oxidative degradation of 

The problems of the photolysis and photochemical reactions of polymers themselves are not considered in the subsequent discussion of the photosensitized reactions of polymers in solutions. This subject has already been examined in Chapter 3 and, moreover, in the majority of cases the photosensitized reactions take place with radiation in the range of wavelengths from 3000 A to 8000 A. 

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