Photo- and thermo-oxidation of polyoctenamer. Photostability of hydroperoxides

The photo-oxidation of polyoctenamer (Vestenamer(R)) has been investigated with the aim of systematic comparison with the photo-oxidation of polybutadiene (BR) which has been extensively studied. The major photoproducts resulting from oxidation have been identified and quantified using well-known derivatization reactions, specific chemical analysis and physical treatments. From the author's results, photochemical evolution of Vestenamer(R) is quite similar to that of BR, exhibiting two steps. In contrast to BR, ketone yield in oxidized polyoctenamer is very significant as the first stage (photo-oxidation) proceeds. In the second phase (photolytic process), photo-oxidation products undergo photolysis implying saturation reactions, and saturated acids appear to be the final photoproducts which accumulate in the polymer. The main difference beetween these two elastomeric materials is the unusually high hydroperoxide content, with a maximum, observed in photo-oxidation of polyoctenamer. (C) 1997 Elsevier Science Limited.