In this work, the effect of coupled degradative conditions (in situ UV irradiation + high temperature) on the rheological
behavior of polyolefins (PP, HDPE, LDPE) in air atmosphere was studied in the photo-rheology method. The UV irradiation
was obtained from mercury lamp and UV LED as an irradiation sources.
We proved that the chain scission reactions occur in PP and crosslinking reactions predominate for LDPE, especially over
180 C. UV irradiation intensifies these effects. We were expecting that LDPE behavior should be a combination of PP and
HDPE. In fact, the HDPE showed the biggest competition between chain-scission and crosslinking reactions, probably by
the fact of higher absorbance. In the case of LDPE, the chain-scission reactions were less intensive.
We showed that both mercury and UV LED can be used as irradiation source. It is necessary to pay attention