Fundamentals of Plasma Polymerization

The plasma polymerization of ethylene is used as an example through which to discuss the elementary steps involved in forming a polymer in an electric discharge. The relationship of the experimentally controlled variables to the rate of formation of first generation active species is discussed. These species are related, in turn, to the overall rate of polymerization through a simple model. Two asymptotic conditions are discussed which correspond to minimal and total conversion of monomer to polymer. The dependence of polymer deposition rate on monomer flow rate predicted by the model is found to correspond very closely to that observed experimentally. The predicted effect of gas pressure on polymer deposition rate also agrees with that found experimentally.