| Abstract: | The kinetics of the accelerated photo-oxidation of low-density polyethylene (LDPE) films has been studied within a range of temperatures, using an ultraviolet radiation enclosure. A simple, lumped parameter, kinetic model was developed to interpret the results of measurements of carbonyl and hydroperoxide absorbances as functions of time; the model predicts, with reasonable accuracy, the general experimental behavior and also that both the formation of hydroperoxides and carbonyl Norrish-I reactions are important initiation steps. Slightly more complex models may thus have the potential of interpreting other fine details of the degradation behavior, namely the generation of other chemical species and the chain scission and cross-linking processes, which are directly related to changes in the mechanical properties. |
