Morphology characterization of high-impact resistant polypropylene using AFM and SALS

Atomic force microscopy and small angle light scattering have been used to characterize the morphology of high-impact polypropylene. Because of sample preparation requirements, both techniques are relatively simple compared with conventional electron microscopy approaches. Using atomic force microscopy the spatial distribution of the impact-modifying ethylene-propylene rubber (EPR) domains could be readily identified whereas small angle light scattering was used to quantify overall domain size distribution. EPR domains from a few hundred nanometers to a few microns in size were observed with average sizes that vary from the edge to the center of the polypropylene particle. In addition, it has been observed that the morphology shifts from discrete domains to bicontinuous as the EPR content is increased.