Response Surface Predictions of the Viscoelastic Properties of Vapor-Grown Carbon Nanofiber/Vinyl Ester Nanocomposites

Nouranian, S., Lacy, T., Toghiani, H., Pittman, C., & DuBien, J. L. (2013). Response Surface Predictions of the Viscoelastic Properties of Vapor-Grown Carbon Nanofiber/Vinyl Ester Nanocomposites. Journal of Applied Polymer Science. 130(1), 234-247. DOI:10.1002/app.39041.

Abstract

A full factorial design of experiments and response surface methodology were used to investigate the effects of formulation, processing, and temperature on the viscoelastic properties of vapor-grown carbon nanofiber (VGCNF)/vinyl ester (VE) nanocomposites. Factors included VGCNF type (pristine, oxidized), use of a dispersing agent (DA) (no, yes), mixing method (ultrasonication, high-shear mixing, and a combination of both), VGCNF weight fraction (0.00, 0.25, 0.50, 0.75, and 1.00 parts per hundred parts resin (phr)), and temperature (30, 60, 90, and 120 °C). Nanocomposite storage moduli were maximized over the entire temperature range (~20% increase over neat VE) by using high-shear mixing and oxidized VGCNFs with DA or equivalently by employing pristine VGCNFs without DA at ~0.40 phr of VGCNFs. Ultrasonication yielded the highest loss modulus at ~0.25 phr of VGCNFs. This study highlights the use of design of experiments to explore complex factorial interactions that cannot be assessed in one-factor experimental studies.