Investigating Domain Distributions in Polymer Composites and Their Influence on Macroscopic Performance Using AFM-IR and AFM-nDMA

The macroscale performance of polymer composites is influenced by both the microstructure of the material and the mechanical properties of microscopic components. As confinement effects and interphase formation can alter the mechanical properties of the microphases, only high-resolution measurements performed directly on the composite can provide the local property distribution needed to understand the relationship between microstructure and bulk.<br/>With its proven ability to map mechanical properties at the nanometer level, Atomic Force Microscopy (AFM) has the resolution and sensitivity needed to investigate these microscopic domains. With careful calibration, nanomechanical results from AFM on homogeneous materials agree with bulk measurements from established rheological techniques like Dynamic Mechanical Analysis (DMA) and Nanoindentation. When AFM based mechanical property mapping techniques are applied to heterogeneous samples like polymer composites, new possibilities emerge for understanding the macroscopic behavior of these materials.<br/>By additionally applying AFM-IR to the sample, it becomes possible to identify the spatial distribution of the chemical components of the composite -- providing insight into how to adjust the sample composition to maximize performance.<br/>This presentation will discuss recent efforts to correlate bulk mechanical properties to nanoscale domain distribution. We will additionally demonstrate how co-located chemical composition maps and nanomechanical maps can be used to better understand composite behavior.