Damping Properties of Epoxy Films with Nanoscale Fillers

Abstract

This study demonstrates improved damping in epoxy films using nanoscale fillers. The mechanism for damping improvement is related to frictional energy dissipation arising from interfacial sliding at the nanofiller-matrix interface. The combination of extremely large interfacial contact area, high aspect ratio, many interfaces, and low density implies that nanoscale fillers could be far more efficient with regard to damping augmentation than traditional fillers. In this study, three categories of nanoscale fillers are investigated; (1) silica nanoparticles, (2) silicon nanorods, and (3) silicon nanosprings. The nanofillers are dispersed in an epoxy matrix and the nanocomposite film is tested dynamically (in the shear mode) using an MTS-858 servohydraulic test facility. The results indicate that nanospring fillers generate greater energy dissipation than nanoparticles or nanorods. The material loss factor (or damping ratio) of the epoxy film (with silicon nanospring fillers) showed a 150% increase compared to the baseline (pure) epoxy. The nanocomposite damping materials developed here show the potential to overcome the limitations of traditional viscoelastic polymers and could help to efficiently deliver significant levels of damping to structural components.