A comparative study of different techniques for microstructural characterization of oil extended thermoplastic elastomer blends

This paper gives a relative comparison of different microscopic methods that are presently used to visualize polymer blend morphologies, versus the possibility to visualize the three-dimensional structure of the blends with electron tomography. Oil extended thermoplastic elastomer (TPE) blends based on a high amount of rubber phase and low amount of isotactic polypropylene (PP) were used as samples for this study. Low voltage scanning electron microscopy (LVSEM) and transmission electron microscopy (TEM) proved to be far superior to conventional scanning electron microscopy (SEM) and atomic force microscopy (AFM) for obtaining good quality images of the morphology of these blends. In an attempt to visualize the 3D morphology, electron tomography was carried out on these blends and models of the 3D morphologies were constructed. The usefulness of the different microscopic techniques in providing complementary morphological information and the potential of electron tomography as a new tool for constructing 3D-models of polymer blends are highlighted.