Preparation of novel hydrophobic magnetic Fe3O4/waterborne polyurethane nanocomposites

Magnetic Fe 3 O 4 /waterborne polyurethane nanocomposites were synthesized based on waterborne polyurethane (WPU) and amino-functionalized Fe 3 O 4 by in situ polymerization. The Fe 3 O 4 nanoparticle was found to be uniformly distributed in Fe 3 O 4 /WPU nanocomposites with linear or crosslinked structure. In addition, the formation mechanism and magnetic conduction mechanism of stable inorganic–organic nanocomposites were discussed. The experimental results showed that the thermal stability, magnetic, and mechanical properties of magnetic Fe 3 O 4 /waterborne polyurethane nanocomposites were improved by amino functionalized Fe 3 O 4 . Furthermore, the defoaming property of the emulsion and the hydrophobic property of magnetic Fe 3 O 4 /waterborne polyurethane nanocomposites were improved by the 1-hexadecanol-terminated prepolymer. What more, polycaprolactone (PCL)-based Fe 3 O 4 /WPU nanocomposites have excellent mechanical properties (The tensile strength is over 30 MPa, the elongation rate is above 300%.) and magnetic properties. Magnetic Fe 3 O 4 /waterborne polyurethane nanocomposites will be used in the field of hydrophobic and microwave absorbent materials. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48546.