XeCl excimer laser-induced graft polymerization on PET surface

Graft copolymerization of acrylamide (AAm) onto poly (ethylene terephthalate) using a XeCl excimer laser was performed to improve surface hydrophilicity. Laser irradiation and graft polymerization were conducted simultaneously. The samples treated were characterized by contact angle measurements, XPS analysis, and microscopic observation. The surface hydrophilicity was improved significantly after AAm was grafted onto the film. The factors influencing the graft reaction were studied to understand the mechanism of laser-induced graft polymerization, deducing that a peroxide-initiated radical polymerization occurs during laser-induced graft polymerization. The N/C ratio of the surface changed from nil for untreated sample and irradiated but non-grafted sample to 0.11 for grafted sample. The O/C ratio increased gradually in the order of untreated, irradiated but non-grafted and grafted under the chosen treatment condition. Carbon particles formed on the grafted surface as higher laser fluence was employed were observed.