A Comparison of Particle Embedment and Nanoindentation: Probing the Surface Properties of Polymeric Materials
ORAL
Abstract
In this work, we report the results from a comparison of viscoelastic surface properties of polymer obtained from two different techniques: the spontaneous particle embedment technique and nanoindentation technique. The surface compliance for polystyrene(PS) and poly(isobutyl methacrylate) (PiBMA) were determined using multi curve fitting method to extract the viscoelastic response from the experimental results. The surface layer rheological properties obtained from particle embedment experiment and indentation are compared both with each other and with the bulk properties. For both materials we observed surface softening when the test temperature is below the macroscopic glass transition temperature. This is followed by a crossover to a surface stiffening region when the test temperature is higher than the macroscopic glass temperature. \textbf{KEYWORDS:} nanoindentation, particle embedment, multi curve fitting method, viscoelastic properties
*Acknowledgements The authors thank the National Science Foundation Grant No. CHE 1112416 John R. Bradford Endowment at Texas Tech University and the Office of Naval Research under Project N00014-11-1-0424, each for partial support of this work.
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