Characterization of active screen plasma modified polyurethane surfaces

In order to improve the surface properties of polyurethane (PU), samples of polyurethane have been surface modified using a newly developed active screen plasma modification (ASPM) technique. The change in the surface topography was investigated by profilometry, atomic force microscopy (AFM) and scanning electron microscopy (SEM); the chemical composition and bonding structure of the plasma modified PU surface were characterized by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR); and the wettability of the modified surface was studied by contact angle and surface energy was calculated. The results show that the ASPM technique not only can effectively alter the surface topography of polyurethane from a closed cell structure to porous open structure but also result in transformation of ester groups into new O-H groups in the top surface layer. The changes of surface topography, structure and chemical composition by plasma treatment have also effectively modified the wettability of the polyurethane surface. (C) 2012 Elsevier B.V. All rights reserved.