Surface modification by low-pressure glow discharge plasma of an unsaturated polyester resin: effect on water diffusivity and permeability

Unsaturated polyester resin (UPR) films have been modified by a tetrafluoro methane microwave plasma. The treated surface morphologies investigated by contact angle, atomic force microscopy and permeation measurements show tha t the CF, plasma treatment decreases drastically the surface energy by incr easing the hydrophobic character. The surface modification due to plasma fl uorination decreases the water content diffusing through the UPR film and t he time lag diffusion coefficient and thus, the sorption kinetic. From thes e results, it is clearly shown that the CF, plasma treated layer improves d rastically the barrier effects. (C) 1999 Elsevier Science S.A. All rights r eserved.