ANGLE RESOLVED ESCA AND ISS STUDIES OF PMMA AND MODIFIED PMMA SURFACES.

Polymethylmethacrylate (PMMA) thin films were studied by Electron Spectroscopy for Chemical Analysis (ESCA) and Ion Scattering Spectroscopy (ISS) to characterize the surface structure of the polymers. The plasma modification process altered the surface in two ways: depletion of O-C equals O and C-O functionalities, and oxygen incorporation in the near surface region. This oxygen incorporation appears to be a water adsorption following polymer modification. The increase in hydrophobicity of the polymer layer from reduction of the argon containing plasma is evident. This accounts for two different processes occurring during modification: 1) oxygen functionality depletion 2) water adsorption from an increase in hydrophobicity. The modified atactic PMMA polymer films (copolymerized with PMAA) were investigated to determine the sensitivity of ESCA and ISS. The data suggests that ESCA is not as sensitive to tacticity and compositional changes for the polymer systems studied, while ISS is very sensitive to these parameters.