Experimental Study of the Dynamic Mechanical Properties of Vapor-grown Carbon Nanofiber/Vinyl Ester Nanocomposites Fabricated Using Coupled High-shear Mixing and Ultrasonication

Nouranian, S., Toghiani, H., Lacy, T., & Pittman, C. (2009). Experimental Study of the Dynamic Mechanical Properties of Vapor-grown Carbon Nanofiber/Vinyl Ester Nanocomposites Fabricated Using Coupled High-shear Mixing and Ultrasonication. In the proceedings of the 2009 Annual Meeting of the American Institute of Chemical Engineers (AIChE), November 8-13. Nashville, TN.

Abstract

Recent advances in the field of polymer nanocomposites and nanophased hybrid composites have provided new opportunities in the design and fabrication of novel light-weight structural materials for use in automotive parts. Though preliminary studies show promising improvements in the mechanical, thermal, and other properties of traditional composites reinforced with small amounts of nanoreinforcing agents including nanotubes, nanofibers, nanoclays, etc., a more systematic study is needed encompassing formulation, mixing, and processing of nanocomposites. This is specifically true because of issues with the dispersion of nanoreinforcements in the polymer matrix and a lack of knowledge with respect to the factors affecting the ultimate properties of interest. In this study, which builds on our previous studies, a designed experimental approach has been employed to study the effect of three formulation factors on the viscoelastic properties of vapor-grown carbon nanofiber/vinyl ester nanocomposites. These factors are: nanofiber weight fraction, nanofiber type (pristine/oxidized), and use of a dispersing agent. The mixing procedure used in these studies was a coupled high-shear mixing/ultrasonication technique. Using analysis of variance and regression techniques, a response surface model was developed for the current design and optimal conditions were determined. The results were further compared to the cases studied previously where the mixing method involved only ultrasonication or high-shear mixing.