Relative variations of nonlinear elastic moduli in polystyrene-based nanocomposites

In this paper we apply the methodology based on the analysis of changes in acoustic wave velocities under static stress for measurements of the third-order elastic moduli in three polystyrene-based nanocomposites with different fillers: SiO2 particles, halloysite natural tubules, and carbon black particles. The samples were fabricated by the same technology and our data provide information on relative changes of nonlinear properties of the composites caused by addition of the fillers. The data obtained for composites are compared with that for commercial grade polystyrene. The substantial variations of the nonlinear elastic moduli for composites with different types of fillers are demonstrated and analyzed. The results are in a qualitative agreement with theoretical predictions.