Photosulfonation of low-density polyethylene films

Photosulfonation of low-density polyethylene (LDPE) films by UV irradiation in the presence of gaseous sulfur dioxide (SO2) and oxygen (O-2) was studied by attenuated total reflectance (ATR) infrared spectroscopy and X-ray photoelectron spectroscopy (XPS). The ATR and XPS analysis and chemical modification of UV-irradiated LDPE films demonstrated the generation of C=C double bonds and sultones in the reaction. These results indicated the possibility that sulfur trioxide (SO3) was produced during the photosulfonation. New pathways for the SO3 reaction with LDPE films, resulting in the formation of sulfonic acid groups, were proposed.