REACTIVITY OF A POLYPROPYLENE SURFACE-MODIFIED IN A NITROGEN PLASMA

The modification of a polypropylene surface in a nitrogen plasma is st udied in terms of degradation, crosslinking, functionalization, and ac tivation (radical site creation.) The most important reactions are fun ctionalization through primary amine formation and radical creation th rough methyl-group elimination. Degradation and crosslinking are compe titive and the latter is more important when the plasma conditions (ex posure time, discharge power) are severe. Exomethylenic bonds (CH2=C) are formed preferentially over crosslinking reactions. Chemical titrat ions are described for radical and amine concentrations on the polypro pylene surface.