In situ stabilized carbon nanofiber (CNF) reinforced epoxy nanocomposites

TLDR

The authors fabricated CNF‑reinforced epoxy nanocomposites by silanizing CNFs with amine groups that react in situ with epoxy monomers, thereby enhancing dispersion and interfacial bonding, and systematically examined how loading, surface treatment, and temperature affect viscosity and modulus. The composites exhibited lower viscosity and higher tensile strength and storage modulus due to improved dispersion and interfacial interaction, while surface‑treated CNFs did not enhance electrical conductivity because of an insulating coating layer.

Abstract

Carbon nanofibers (CNFs) suspended epoxy resin nanocomposites and the corresponding polymer nanocomposites are fabricated. The surface of CNFs is introduced a functional amine terminated groups via silanization, which in situ react with epoxy monomers. This in situ reaction favors the CNFs dispersion and improves the interfacial interaction between CNFs and monomers. Effects of particle loading, surface treatment and operating temperatures of rheological tests on the complex viscosity, storage modulus and loss modulus are systematically studied. Unique rheological phenomena "a decreased viscosity with a better dispersion" are observed and explained in terms of the improved filler dispersion quality. Meanwhile, significant increase in the tensile property and storage modulus is observed and related to the better dispersion and the introduced strong interfacial interaction as revealed by SEM imaging. Finally, electrical conductivity is investigated and an unusual deficiency of surface treatment to improve the electrical conductivity is explained by an insulating coating layer.