(461a) Interfacial Failure of Polymer/Nanoparticle Interface and Its Influence to Flow Properties of Polymer Nanocomposites

The challenging of understanding polymer mechanics and dynamics at the interface is shared by multiple sub-disciplines including thin film, polymer nanocomposites, adhesion and wetting, coating, tribology, etc. While a large quantity of recent efforts focuses on unraveling the segmental dynamics at the interfacial layer between the polymer and the solid surfaces, the chain dynamics at the interface, that is of high relevance to processing and manufacturing, received much less attention . In this work, we aim to study the interfacial instability, namely the desorption/adsorption processes of interfacial polymer, and their relationship to the flow properties of polymer nanocomposites. With Rheo-dielectric measurements, we not only are able to monitor the interfacial failure process (the polymer detachment at the nanoparticle surface) under external deformation and stress, but also can quantify the correlation between the external deformation and the number of polymers undergoing desorption process. Interestingly, we found the ability to flow of polymer nanocomposites increases significantly only when the anchored polymer segments start to detach from the nanoparticle surface. We believe these observations will have strong implications for the processing design of polymer nanocomposites.