Nanomechanic properties of polymer-based nanocomposites with nanosilica by nanoindentation

The nanocomposites consist of nanometer silica fillers embedded in thermoset polymers, which were prepared by means of irradiation of ultraviolet light. The nanomechanic properties had been investigated by load-displacement analysis from nanoindentation experiments. The results obtained showed that the nanoindentation hardness is decreasing and tends to a certain value with increasing indentation depth, the value is among 1.91-4.11 GPa while the nanosilica contents varied from 0 to 5% within nanocomposites. Young's modulus measured by nanoindentation is higher than the value by tensile test, namely E-I/E-T=2.63 and the enhancement of Young's modulus due to the presence of nanosilica with the above contents, E-I/E-1.0=1.7-2.0 from nanoindentation test and E-T/E-T.0=1.8-2.2 from tensile test, was compared to be consistent with each other in two different methods. So nanoindentation technique has been successfully applied for the valuation of the nanomechanic properties of nanocomposites with nanosilica.