Improved mechanical property, water resistance of waterborne polyurethane films by incorporating nano precipitated calcium carbonate

In this work, we investigate the possibility of using nano precipitated calcium carbonate (NPCC) to enhance the water resistance of waterborne polyurethane (WPU) with excellent mechanical properties. NPCC were firstly synthesized by carbonization and surface modified with WPU10001 in situ. Then a series of WPU-NPCC films were prepared by blending WPU1000 modified NPCC with WPU. The results showed that the loading of nano-CaCO3 was added at 2 wt%, tensile strength was significantly increased from 24.9 MPa to 49.6 MPa, elongation at break was increased from 325.4 % to 450.1 %, and water absorption was reduced from 12.3 % to 3.2 %. This work provided a simple and low-cost approach for developing waterborne polyurethane with high mechanical properties and excellent water residence.