PREPARATION OF HYDROPHILIC PLASMA-POLYMERS DERIVED FROM OXYGEN-CONTAINING ORGANIC MONOMERS

Plasma polymerization of nine oxygen-containing organic monomers was s urveyed for producing hydrophilic films on solid substrates on due con sideration of chemical structures of the monomers, operative condition s for plasma polymerization, and resultant film characters. The wettab ility of the polymer films were evaluated by measuring the contact ang les of water on the film surfaces while the power consumption was comp ared as the lowest wattage needed for sustaining normal deposition rat es of the polymer films. It has been found that the monomers involving the triple bond in the chemical structure conducted plasma polymeriza tion under very low wattage of radiofrequency power, and at the same t ime the deposition rate was relatively high. With respect to the chemi cal structures of the monomers, the hydroxyl group tended to initiate and sustain the electric discharge at somewhat lower power than other functional groups. Highly hydrophilic polymer films could, thus, be ob tained under a soft plasma condition by using propargyl alcohol (2-pro pyn-1-ol) as a monomer having the triple bond and the hydroxyl group. X-Ray photoelectron spectra of the polymers suggested that the wettabi lity was not simply dependent upon oxygen atom content of the polymers , but also dependent upon spatial arrangement of the oxygen atoms with in the polymer molecules. (C) 1996 John Wiley & Sons, Inc.