Preparation and properties of amino-functional reduced graphene oxide/waterborne polyurethane hybrid emulsions

In this study, we provided a novel method to prepare amino-functional reduced graphene oxide/waterborne polyurethane (rGO/WPU) hybrid emulsions. Firstly, the silane-functionalized reduced graphene oxide (A-rGO) with free amine groups on its surface was prepared via the modification of GO with 3-aminopropyltriethoxysilane (APTES) and the reduction by diethanol amine (DEA). Then, the obtained A-rGO sheets were incorporated into polyurethane by in situ polymerization to prepare A-rGO/WPU hybrid emulsions. The results from Fourier transform infrared spectroscopy (FTIR), X-Ray Diffraction (XRD), thermal gravity analysis (TGA), and Raman spectra clearly indicated that APTES was grafted on the surface of GO, and GO was reduced by DEA. With the increase of A-rGO content, the glass transition temperature, mechanical property, storage modulus, and thermal stability of A-rGO/WPU films increased gradually due to the homogeneous dispersion of A-rGO sheets in the WPU matrix and the strong covalent interaction between A-rGO sheets and WPU matrix. When the content of A-rGO sheets was 0.5 wt%, the A-rGO sheets could homogeneously dispersed in the WPU matrix, and the A-rGO/WPU films exhibited excellent overall performance.