Comb-Like Fluorinated Polystyrenes Having Different Side Chain Interconnecting Groups

Comb-like fluorinated polystyrenes with different side chain interconnecting groups between backbone and side chain, such as ether (PST-O), thioether (PST-S) and sulfone (PST-SO2), were synthesized in order to examine the effect of the interconnecting groups on the surface order and properties. Near edge X-ray absorption fine structure spectroscopy and grazing incidence wide-angle X-ray diffraction showed that PST-SO2 with very polar sulfone groups exhibited a lower tilt angle of the fluorinated helix to the surface normal as well as higher packing density of fluorinated alkyl side chains than PST-O and PST-S, which have less polar groups. As a result of the ordered structure at the polymer-air interface, PST-SO2 has a smaller surface energy and better stability in water than PST-O and PST-S. These results suggest that the introduction of polar groups to the side chains of comb-like fluorinated polymers can improve the surface properties including the hydrophobicity and stability of fluorinated surfaces.