Preparation and characterization of well-dispersed waterborne polyurethane/CaCO3 nanocomposites

In this study, in order to improve the dispersion and increase the compatibility between nanoparticles and waterborne polyurethane (WPU) matrix, CaCO3 nanoparticles were firstly modified with oleic acid (OA). A series of WPU/CaCO3 nanocomposites were prepared by further in situ polymerization. SEM examination of the fractured surfaces of nanocomposites showed that OA–CaCO3 achieved well dispersion in WPU matrix. FTIR analysis suggested no major changes in the chemical structure of WPU in the presence of 2 wt% CaCO3. Thermal stability of WPU measured by TGA was greatly improved with the addition of OA–CaCO3. Meanwhile, the mechanical properties of the nanocomposites, examined by tensile tests, showed higher tensile strength than that of the pure WPU, especially incorporation of OA–CaCO3.