Atmospheric Pressure Non-Equilibrium Plasma Deposition with Retention of Functional Group

A non-equilibrium atmospheric pressure plasma was applied for the polymerization of the methacrylic monomers such as (2-hydroxyethyl methacrylate (HEMA), methacrylic acid (MAA) and butyl methacrylate (BMA)). These monomers were successfully polymerized with retaining the functional groups of ester or acid. The polymerization mechanism was discussed on the basis of the optical emission spectroscopy (OES) of the plasma. It was strongly suggested that the functional groups could be retained in the polymerization proceeds when the HOMO-LUMO gap of the monomer is close to the energy of Ar metastable atom, which initiates the polymerization.