Abstract:Polyurethane prepolymers were prepared with isophorone diisocyanate (IPDI), poly(propylene glycol) (PPG) and N,N-dimethyl-N'',N''-di(2-hydroxypropyl)-1,3-propanediamine. Acetic acid, citric acid and 2,2-dimethylolpropionic acid (DMPA) were used as salt-forming agent to react with the polyurethane prepolymer to prepare three kinds of ionized polyurethane, and then they were emulsified in water to obtain three kinds of waterborne polyurethane latexes which were abbreviated as WPU1, WPU2 and WPU3, respectively. Three kinds of waterborne polyurethane films were prepared from the latexes and immersed in simulated seawater to absorb CO2 and mineralize to form polyurethane-calcium carbonate (PU-CaCO3) composite films and their anticorrosion properties were studied. The process of three kinds of waterborne polyurethane films to absorb CO2 and mineralize to form polyurethane-calcium carbonate (PU-CaCO3) composite membranes and their anti-corrosion properties were studied. FT-IR results show that three kinds of cationic waterborne polyurethane were successfully synthesized. The particle size test shows that the particle sizes of WPU1, WPU2 and WPU3 latexes are 19.38 nm, 93.08 nm and 84.33 nm, respectively. XRD, SEM and electrochemical test results show that after the simulate seawater immersion, the CaCO3 mineralization layer appears on both WPU2 and WPU3 film surface. The mineralization layer formed on the surface of WPU3 film is relatively dense and has excellent anticorrosion properties, and its corrosion rate and corrosion current density are 1.70×10-3 mm/a, 1.44×10-7 A/cm2.