Polyethersulfone (PESU) and Polysulfone (PSU) are aromatic thermoplastics that demonstrate excellent mechanical properties and hydrolytic stability leading to applications in filtration membranes, biomedical devices, and high performing coatings. However, such applications require precise control of surface composition, structure, and properties. Thus, post processing surface modifications are often necessary in order to meet the performance requirements. We have previously reported the preferential surface segregation of polyhedral oligomeric silsequioxane (POSS) additives in POSS/polyphenylsulfone nanocomposites prepared by melt blending. While POSS segregation can have a dramatic effect of the surface properties of polymer systems, the aggregation size and crystallinity can be difficult to control in a melt blended composite. However, modifying polymer chain ends (CEs) with POSS analogues results in a covalent attachment to the polymer chain and allowing for more uniform POSS surface coverage. Additionally, the preferential segregation of POSS CEs near the air-interface is an alternative route to exploit the desirable POSS properties at the surface of the polymer while maintaining the bulk polymer properties (i.e. low concentration of CE’s in the bulk). Herein we report the synthesis and characterization of perfluorocyclopentenyl (PFCP)-POSS end-capped sulfone polymers. PFCP-POSS structure and grafting efficiency of the POSS molecules to the polymer chain was verified via fluorine (19F) NMR. Surface composition and depth profiles were measured using X-ray photoelectron spectroscopy (XPS) and neutron reflectivity (NR) techniques. Crystallinity of the POSS modified systems was investigated via X-ray diffraction (XRD). Finally, the surface properties of solution cast films were characterized with quantitative nano-mechanical mapping-atomic force microscopy (QNM-AFM) and contact angle goniometry.

Functionalization and surface characterization of sulfone polymers with partially fluorinated POSS chain-ends

251st National Meeting (2016)

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