Characterization of Viscoelastic Behavior of Poly(dimethylsiloxane) by Nanoindentation

摘要

In this study, we characterize the viscoelastic behavior of polymers using nanoindentation. We applied the indentation representative stress approach and elastic solution to the Maxwell model and determined that there was a linear relationship between the inverses of the initial unloading stiffness and indentation unloading rate. From nanoindentation tests with various unloading rates on poly (dim ethylsiloxane), the linear relationship between the indentation unloading rate and the initial unloading stiffness was confirmed. We have suggested two parameters such as, elastic coefficient and viscous coefficient, represent the viscosity and elasticity of the polymer material based on their relation. In order to check the dependency of the elastic and viscous coefficients on mechanical properties, we performed nanoindentation on poly(dimethylsiloxane) with different crosslinking densities by mixing different proportions of curing agent. The viscosity and elasticity depend on the crosshnking density of polymer, and it was confirmed that the elastic coefficient and viscous coefficient obtained from nanoindentation varied with the same trend depending on crosshnking density.