On the use of nanoscale indentation with the AFM in the identification of phases in blends of linear low density polyethylene and high density polyethylene

The microstructures generated by blends of linear low density polyethylene (LLDPE) and high density polyethylene (HDPE) following isothermal crystallization from the melt have been studied using several techniques. The traditional methods of electron microscopy, wide angle X-ray scattering, and differential scanning calorimetry were used to examine the superstructures, lattice spacings, and thermal properties, respectively. In addition, nanoindentation of specific moieties within the microstructure was performed using the atomic force microscope (AFM). The indentation measurements were used to generate values for the relative elastic moduli of the crystalline features and to identify phases within the superstructures. The AFM results were compared to results obtained from the aforementioned techniques and to microhardness measurements.