Preparation of Polymer Films by Radical Beam

Abstract

Radical species were separated from O₂, N₂ and Ar plasmas formed by the glow discharge at 20 kHz frequency, and then used as initiation agents for surface modification and thin film formation. The concentration of radicals separated from the plasmas depended on the pressure of the reaction chamber (Table 1) as well as the distance from the plasma generator (Fig.4). When polyethylene sheets were exposed to the radical beams, the surface was modified to be hydrophilic (the surface energy of the modified was ca.60 kN/m) (Table 2). Thin films were deposited by exposing stryrene vapor to the radicals. However the polymer deposition rate was retarded to a quarter compared with that by exposure to plasma. The chemical composition of the polymer was fairly different from that of plasma polymers from styrene but similar to conventionally polymerized polystyrene. This result suggests that a less degraded polymer films, especially with less degradation in the phenyl group, could be formed by the radical beam compared with plasma polymerization.