PLASMA POLYMERIZATION: XI. A COMPARISON OF THE PLASMA POLYMERIZATION OF THE ISOMERIC PERFLUORINATED DIAZINES.

In the reported experiments, plasma polymers synthesized by inductively coupled RF techniques have been investigated as a function of operating parameters for the isomeric perfluorinated diazines (pyrazine, pyrimidine, and pyridazine). A combination of ESCA and microanalytical studies shows that plasma polymers are produced by rearrangement mechanisms: the C/F and C/N stoichiometric ratios are similar to those of the starting monomers over a range of operating parameters. A comparison of rates of formation of plasma polymer films reveals distinctive differences between the isomeric diazines that suggest that equilibration of valence isomers occurs on a substantially slower time scale than for isomeric fluorinated benzenes which, in general, polymerize at essentially the same rates. In contrast to the remarkably low critical surface tension of plasma polymers based on perfluorobenzenes (ca. 20 dynes cm** minus //2), the plasma polymer films from the perfluorinated diazines which are initially hydrophobic become hydrophilic in contact with water droplets.