Article révisé par les pairs
Résumé : The molecular weight distribution of low density polyethylene-linear low density polyethylene blends, photo-oxidized in natural weathering conditions, has been studied. The exposure conditions cover different periods of the year from May to December, and so a broad range of intensities, total incident energy and weather. A good correlation between the results corresponding to these different conditions has been obtained using the global incident energy and a simple model for its spectral distribution. Main chain scission is the main process but some crosslinking has also been detected. Preferential degradation of LLDPE could not be observed. © 1990.