QUANTIFICATION OF THE FUNCTIONAL-GROUPS PRESENT AT THE SURFACE OF PLASMA POLYMERS DEPOSITED FROM PROPYLAMINE, ALLYLAMINE, AND PROPARGYLAMINE

The surface chemistry of plasma-deposited films created from amine-functionalized saturated (propylamine) and unsaturated (allylamine and propargylamine) precursors has been investigated by high-energy resolution XPS, chemical derivatization, elemental analysis, and HREELS. XPS results show that nitrogen-rich deposits are obtained from unsaturated precursors at low power or at high power in the postdischarge region. Quantitative information on the chemical groups in the polymers is obtained by simulating the XPS C1s and N1s core levels and by performing derivatization reactions. The proportion of primary amine functions deduced from tagging reactions with pentafluorobenzaldehyde in the liquid phase and with 4-trifluoromethylbenzaldehyde in the vapor phase varies between 10 and 33%. These groups are converted into imine (more than 50%) in polypropylamine and polyallylamine, while imine and nitrile functions were found in polypropargylamine. HREELS has allowed us to distinguish between different nitrogen-containing functionalities present at the extreme surface of the polymers. The comparison of the HREELS and TIR spectra shows that the chemical composition at the extreme surface of the samples is representative of that of the bulk. To explain the conversion of the chemical groups in the plasma, polymerization mechanisms are proposed for each of the monomers. (C) 1995 John Wiley and Sons, Inc.