Synthesis and mechanical properties of dopamine modified titanium dioxide/waterborne polyurethane composites

Environmentally friendly waterborne polyurethane (WPU) films were functionalized by incorporating nano‐titanium dioxide (TiO 2 ). In order to improve the dispersion of TiO 2 in the WPU matrix and intensify the interfacial interaction between TiO 2 and WPU, green and biocompatible dopamine (DA) modified TiO 2 , that is, DA‐TiO 2 , was produced. Fourier transforms infrared (FTIR) and UV‐vis spectra confirmed that DA had been successfully grafted on the surface of TiO 2 . The structure, mechanical and thermal properties of WPU/DA modified TiO 2 (WPU/DA‐TiO 2 ) films had been carefully investigated using FTIR, transmission electron microscopy (TEM), X‐ray diffraction (XRD), tensile experiments and thermogravimetric analysis (TGA). The tensile strength and elongation at break of WPU/DA‐TiO 2 containing 1 wt% DA‐TiO 2 increased by 56.8% and 37.0%, respectively, compared to pure WPU. These results can be ascribed to the good dispersion of DA‐TiO 2 and the strong interfacial interaction between DA‐TiO 2 and WPU matrix. In addition, the thermal properties and water resistance of WPU/DA‐TiO 2 films also had been improved. POLYM. COMPOS., 40:328–336, 2019. © 2017 Society of Plastics Engineers