Characterization of the interfacial properties of modified polypropylene

The interfacial properties of a rubber blended polypropylene were investiga ted by the combination of complementary techniques in order to characterize the effects of different surface treatments. The wettability was investiga ted by contact angle measurements with water, streaming potential measureme nts indicated the Bronsted acidity/basicity of the surfaces, and X-ray phot oelectron spectroscopy (XPS) identified the chemical elements, which were i ncorporated by the various treatments. The topography and the roughness of the samples were quantitatively analyzed by scanning force microscopy (SFM) . Direct force measurements showed the possibility of changing the sign of the surface charge by choosing suitable buffer solutions, leading to attrac tion and repulsion to the Si3N4 tip, respectively. In the case of technical -type polymer samples used in this study, direct force measurements are in exact agreement with the streaming potential measurements and offer a valua ble tool for interface characterization.