SURFACE MODIFICATION OF POLYPROPYLENE IN OXYGEN AND NITROGEN PLASMAS

We have studied in detail the surface modification of polypropylene (PP) in low pressure plasmas of oxygen or nitrogen. As revealed by electron spectroscopy for chemical analysis, contact angle measurements and scanning electron microscopy, the plasma ensures a quick functionalization of the PP surface with O- and N-containing chemical groups within a few seconds, while a roughening of the surface topography takes place on a distinctly enlarged time scale. The plasma configuration and processing conditions are found to be key parameters for achieving a most effective and economical plasma treatment process. When plasma treated under optimized conditions, PP shows an excellent performance in application tests (e.g. adhesive polymer-metal bonding, adhesion of water-based coatings).