Deformation induced changes in surface properties of polymers investigated by scanning force microscopy

In this study the possibility of combining commercial Scanning Force Microscopes (SFM) with stretching devices for the investigation of microscopic surface changes during stepwise elongation is investigated. Different types of stretching devices have been developed either for Scanning Platform-SFM or for Stand Alone-SFM. Their suitability for the investigation of deformation induced surface changes is demonstrated. A uniaxially oriented polypropylene film is stretched vertically to its extrusion direction. The reorientation of its microfibrillar structure is investigated and correlated to macroscopic structural changes determined by taking a force-elongation curve. Microtome cuts of natural rubber filled with 15 PHR carbon black are stretched. Changes in topography, local stiffness and adhesive force are simultaneously reported by using a new imaging method called Pulsed Force Mode (PFM).