This work is dedicated to the modeling of the aging process of polyethylene exposed to a reactive plasma. Specifically, we present a comparison between two different models. The first model, already present in the literature, involves H-extraction due to O and OH radicals and their subsequent reaction with additional species present in the gas. The second model, in addition to the reactions of the first, is enhanced by including effects such as H-extractions and absorptions due to collisions of various ionic species with the surface. These collisions were reproduced through ab-initio molecular simulations. The performance of both models was verified by implementing them in a simulation code that represents the interaction between a plasma and a polymeric surface. The results were compared with experimental data available in the literature.
The first model is capable of experimentally reproducing the increase in oxidation observed in polymeric surfaces exposed to plasma discharges. The second model, which includes the effects of NO radical interaction on a surface that was previously oxidized, is able to explain the presence of nitrogen on the surface.