(412a) Nanoparticle, Segmental and Chain Dynamics in Polymer Nanocomposites

Polymer nanocomposites encompass a wide variety of systems comprised of thermoplastics or thermosets and nanoparticles of various shapes and sizes. While a few polymer nanocomposite systems have very well-established applications, the scope of these materials could be expanded further, perhaps even into construction and infrastructure applications that require improved creep performance. Creep describes the long-term deformation under a static mechanical load and the nanoparticle, segmental, and chain dynamics are critical to understanding and improving creep behavior in polymer nanocomposites. This talk will focus on the dynamic properties of polymer nanocomposites wherein there are either neutral or favorable interactions between the nanoparticles and thermoplastics. Using a combination of experimental methods (single particle tracking, ion beam methods, dielectric spectroscopy, modulated DSC, and quasielastic neutron scattering), a comprehensive description of the nanoparticle diffusion and hierarchical polymer dynamics has emerged. The importance of nanoparticle dispersion on dynamics will also be discussed as the connection from nanoscale dynamics to macroscopic mechanical properties is developed.