Adhesion and hydrophilicity of glow-discharge-polymerized propylene coatings

The glow-discharge polymerization of propylene has been studied using an electrodeless electromagnetically coupled (inductive coupling perpendicular to the reactor) tubular reactor operating at a radio frequency of 27.1 MHz. The effects of monomer flow rate (or reactor pressure at constant pump speed), polymerization time, and substrate position on the adhesion of polymeric film to glass and aluminum have been determined. Conditions have been found for excellent adhesion to a substrate. Improvement of the hydrophilicity of the glow-discharge-polymer surface has been achieved by oxygen etching.