Preparation and properties of amine-functionalized reduced graphene oxide/waterborne polyurethane nanocomposites

Abstract

Amine-functionalized reduced graphene oxide (NH2-RGO), with primary amine (—NH2) groups linked onto surfaces by toluene-2,4-diisocynate), was successfully synthesized. Subsequently, the as-prepared NH2-RGO nanoplatelets were covalently incorporated into a waterborne polyurethane (WPU) matrix to fabricate NH2-RGO/WPU nanocomposites by the reaction of —NH2 groups with the isocyanate-terminated polyurethane prepolymer. Electron microscopic observations confirmed that the NH2-RGO nanoplatelets were homogenously dispersed in the WPU matrix. The NH2-RGO/WPU nanocomposites exhibited a significant improvement in their mechanical and thermal properties. The tensile strength and storage modulus of the nanocomposites increased by 73% and 973%, respectively, with the addition of 1.0 wt% NH2-RGO. The thermal degradation temperature was enhanced by about 40°C compared with the neat WPU. Meanwhile, the thermal conductivity increased by about 258%.