Fabrication and properties of novel superparamagnetic, well – Dispersed waterborne Polyurethane/Ni–Zn ferrite nanocomposites

Novel superparamagnetic nanocomposites based on covalently linked waterborne polyurethane (WPU) and Ni0.3Zn0.7Fe2O4 ferrite nanospheres (NZFO) were successfully synthesized using an in situ polymerization method. The Ni0.3Zn0.7Fe2O4 nanoparticles prepared by a typical solvothermal method were modified with 3-(triethoxysilyl) propyl isocyanate (IPTS) to improve the compatibility with monomers. The functionalized NZFO nanoparticles (NZFO-IPTS) served as effective cross-link points and reacted with the WPU matrix, forming chemical bonds. It was found that the NZFO-IPTS greatly improved the dispersibility of NZFO nanoparticles in the WPU matrix, and the introduction of NZFO-IPTS enhanced the thermal behavior and mechanical properties of the WPU polymer. What's more, the WPU/NZFO nanocomposites presented superior magnetic properties and a maximum saturation magnetization (Ms) of 16.58 emu/cm3 was observed, thus illustrating the potential applications of the generated materials in microwave-absorbing fields.