Plasma polymerization of ethylene in an atmospheric pressure‐pulsed discharge

The polymerization of ethylene in an atmospheric pressure‐pulsed discharge has been studied. Partial pressures of ethylene up to 4 kN/m2 were used with helium as a diluent. Deposition rates (on glass slides) were the same throughout the discharge volume over a wide range of operating conditions. These rates were in the 1–2 Å/sec range. The films were clear, soft, and showed good adhesion to the glass substrates. Oligomers large enough to visibly scatter 637.8‐nm light were observed in the gas phase under all conditions in which film deposition occurred. The experimental results suggest that Brownian diffusion of these oligomers was the rate‐limiting step in the film deposition process.