XPS investigations of nitrogen-plasma-treated polypropylene in a reactor coupled to the spectrometer

Nitrogen plasma treatments that modify polymer surfaces are often accompani ed by uncontrollable oxidation phenomena. Air exposure of the treated sampl es after the plasma process may be the origin of the oxidation, but other o xygen contamination sources during the plasma treatment procedure cannot be eliminated. To clarify this point, nitrogen plasma treatments of polypropy lene are carried out in a reactor that is coupled directly to an XPS spectr ometer, This avoids any air transfer of the polymer between its plasma trea tment and its surface characterization. The results indicate a certain leve l of oxygen incorporation in the polymer during the plasma process, probabl y by species coming from the reactor wall. Copyright (C) 2000 John Wiley & Sons, Ltd.