| Nanocomposite materials are of great current interest because the nanometer-scale component offers the potential for new and improved properties. When incorporated into a polymer matrix, these high surface area fillers have been reported to significantly improve properties such as stiffness, strength, toughness, etc. It has been reported that high-intensity, probe-style ultrasonic processing can effectively break up and disperse nanoparticle agglomerates to form polymer matrix nanocomposites with uniformly dispersed fillers. In this undertaking, the knowledge of sonication's effects on the polymer matrix is essential for a complete understanding of the composite's final properties. For this purpose, we conducted Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and 3-point bending flexural measurements on an epoxy resin. Our FTIR results showed that ultrasonic processing increased the IR intensity of various oscillators and that this increase was at least partially reversible with time. DSC measurements, however, confirmed no change in the epoxy's glass transition temperature (T g). Sonication appeared to increase the storage modulus of the cured epoxy, primarily at lower temperatures, but did not appear to significantly affect the flexural mechanical properties.;We also fabricated nano-titanium oxide (TiO2) epoxy matrix composites to explore the ability of sonication to achieve good dispersion and used transmission electron microscopy (TEM), DSC, DMA, and 3-point bending measurements to characterize the composites, while focusing on how the nanoparticle shape and filler loading affected the material's properties. TEM images showed that, while sonication was able to considerably improve the dispersion of the nanoparticles within the epoxy, approximately 1 mum agglomerates remained throughout the composites. The Tg as well as the flexural mechanical properties of the epoxy did not appear to be significantly altered by the addition of the TiO2. Small improvements in storage modulus were observed for certain filler contents. |
