(201d) Predicting the Coupled Development of Flow Induced Nanostructure, Rheology, and Performance Properties of Polymer/Nanoparticle Composites

There has been much interest and research in layered silicate based polymer nanocomposites (PNCs) and carbon nanofiber (CNF) based PNCs in recent years because of the potential to create materials with enhanced mechanical, thermal, electrical, and barrier properties while using much lower particle loadings than traditional fillers. The anisotropic nature of these two nanoparticles makes the rheological processing and mechanical performance properties of the PNC greatly dependent upon the orientation and dispersion of the particles within the polymer matrix. There have been numerous studies demonstrating the connection between bulk phase properties and microstructure, and several theoretical models have been proposed to predict the rheological behavior of nanocomposites, however, there have been few attempts to combine theoretical models with steady shear, transient shear, and transient extensional shear experimental results. We have produced a model that predicts the 3-dimensional development of nanoparticle orientation and the resulting rheology within a PNC during its melt phase flow. The predictions from this flow-based model are then used to predict the performance properties (e.g. electrical conductivity) of a solidified PNC. The predictive capability gained from this model will aid in the design of manufacturing processes for PNC components which tailor nanoparticle orientational distributions and heterogeneity, which in turn result in prescribed multi-functional properties.