Quantitative mapping of elastic moduli at the nanoscale in phase separated polyurethanes by AFM

Nanoscale mechanical properties of segmented polyurethanes have been investigated by two novel dynamic imaging modes of AFM. Varying stoichiometric ratio of isocyanate and hydroxyl groups resulted in polyurethanes samples with characteristic fingerprint AFM phase images. AFM resolves the elastic moduli of stiff and soft segments of the phase separated polyurethane samples at nanoscale resolution. Mechanical mappings were in excellent agreement for both modes, opening novel avenues for nanoscale mechanical characterization of heterogeneous polymers.