The fluoropolymer composed of styrene and 4-fluorine styrene was grafted from the surface of PET films via surface initiated atom transfer radical polymerization (SI-ATRP).The influences of different grafting times and composition of monomers on the surface composition

structures and morphology were studied.The surface composition and structures of the modified PET films were characterized by X-ray photoelectron spectroscopy (XPS)

Fourier transform infrared spectroscopy (FTIR/ATR) and gel permeation chromatography (GPC).And the results could confirm the successfully grafting of initiators and polymers from the surface of PET films.The surface properties were measured by contact angle measurements.The data of contact angle showed that the surface properties of PET films were related to the reaction time and monomer percentage.As the reaction time increased

the grafting rate and the contact angle of PET films increased

but the surface energy decreased.The contact angle increased from 68? to a maximum of 98? after modifications

and the maximum of the grafting rate reached 20.33%.The surface morphologies of PET film and modified PET film were studied by SEM.After modification the PET film surface had been changed from smooth surface into rough surface.