Effect of a plasma treatment on water diffusivity and permeability of an unsaturated polyester resin

Unsaturated polyester resin films have been modified by a tetrafluoromethane microwave plasma. The treated surface morphologies investigated by contact angle, atomic force microscopy and permeation measurements show that the CF4 plasma treatment decreases drastically the surface energy by increasing the hydrophobic character. The surface modification due to plasma fluorination decreases the water content diffusing through the UPR film and the time-lag diffusion coefficient and thus, the sorption kinetic. From these results, it is clearly shown that the CF4 plasma treated layer improves drastically the barrier effects.