Investigation of polyurethane (urea)/modified nano-calcium carbonate hybrid aqueous dispersions and their films

This investigation was focused on properties of polyurethane (urea) (PUU) by incorporating silica sol-modified nano-calcium carbonate (CaCO₃). The FT-IR spectroscopy and ζ potential measurement indicated the presence of a hybrid effect due to the hydrogen bonding between the nano particles and the polymer matrix. For these hybrid aqueous dispersions, the particle size decreased as the modified nano-CaCO₃ content increased, and the polydispersity index was very narrow (<1.20). Films prepared with the hybrid PUU aqueous dispersions exhibited excellent waterproof performance: the amount of water absorption was as low as 9.0 wt %, and the contact angle of water on the surface of this kind of film was as high as 93°C. TGA results indicated the high thermal stability of hybrid PUU polymers (223–255°C). The properties like tensile strength, hardness, and elongation at break were influenced by the modified nano-CaCO₃ content in the polymers. The hybrid PUU with 15 wt % modified nano-CaCO₃ content showed the optimum properties. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012