Surface characteristics of cyanoethyl cellulose grafted with fluorine-containing acrylate

To introduce superior water repellency and functional properties to the air-polymer and the glass-polymer interfacial regions of solvent cast cyanoetyl cellulose (CEC), attemps were made to graft fluorine-containing acrylate (PPA) onto it. The chemical structure and morphology of the surface formed in response to the interface environment and the film thickness at the time of solvent casting were studied. The surface chemical analysis was carried out by X-ray photoelectron spectroscopy (XPS), and the distribution of CEC and PPA polymer phases was mapped using force modulation microscopy (FMM) and phase detection imaging (PDI) of an atomic force microscope (AFM). By XFS analysis it was shown that the air-polymer interfacial region consisted mainly of PPA polymers with low critical surface tension, irrespective of the film thickness, but the glass-polymer interfacial region consisted of a mixtire of CEC and FPA polymers. Furthermore, AFM analysis revealed that the chemical structure of the glass-polymer interfacial region was influenced by film thickness, and a well-defined sea-island-type phase-separated structure was observed at the glass-polymer interface for the film 22 mum thick. It was shown that domains of PPA polymer of the order of several hundred nm were formed in the CEC phase.