Tof-SIMS and XPS surface characterization of novel perfluoropolyether-urethane ionomers from aqueous dispersions

In this work a new class of ionomeric block Perfluoropolyether (PFPE) polyurethanes are presented; these polymers are obtained in form of aqueous dispersion due to the presence of hydrophilic sites (ionomeric groups as acetates or trialkylammonium salts) along the macromolecular chain, offering the chance to combine PFPEs in a variety of possible structures for coating of surface treatments with an environmentally friendly use. X-ray Photoelectron Spectroscopy (XPS) analysis, at two different sampling depths, as well as Time Of Flight-Secondary Ion Mass Spectrometry (TOF-SIMS) analysis, modeled by the use of Principal Component Analysis (PCA), were used to investigate the first nanometers of the surface samples. It resulted in a clear surface enrichment in fluorine, and the different extent of the fluorine stratification will be discussed in relation to the ionic character, film forming from water, and cross-linkin