Micromechanical properties of elastic polymeric materials as probed by scanning force microscopy

Scanning force microscopy (SFM) was used for probing micromechanical properties of compliant polymeric materials. Classic models of elastic contacts, Sneddon's, Hertzian, and JKR, were tested for various indentation depths and for a variety of polymeric materials. We selected extremely compliant polyisoprene rubbers (Young's modulus, E = 1-3 MPa), elastic polyurethanes (E = 5-50 MPa), and hard surfaces of polystyrene (PS) and polyvinylchloride (PVC) (E = 1-5 GPa). Both Sneddon's and Hertzian elastic models gave consistent and reliable results in the range of indentation depths up to 200 nm which are close to JKR solution. Close correlation is observed between absolute values of elastic moduli determined by SFM and known values for bulk materials.