Nanoscale thermal analysis of multiphase polymer nanocomposites

Understanding the structural and thermomechanical properties of mixed-phase polymeric materials and composites at the nanoscale is one of the key challenges in developing a new class of materials with improved structural properties. Here, we present a nondestructive method, local thermal analysis (LTA), based on a heated atomic force microscope cantilever, for the nanoscale characterization of structural and thermal properties of polymer composites. The technique allows measurement of the local melting point, the dehydratation temperature, and the thermal expansion. Moreover, by monitoring the indentation with the heated tip after the melting point, the LTA may be used for phase assignment in multilayered polymers. The measured melting temperatures are found to be reproducible and match satisfactorily with those obtained by differential scanning calorimetry. Finally, the LTA technique coupled with transmission electron microscopy allows us to obtain a more precise description of the nanostructure of a recently developed cellulose/PEO nanocomposite.