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

Abstract Novel superparamagnetic nanocomposites based on covalently linked waterborne polyurethane (WPU) and Ni 0.3 Zn 0.7 Fe 2 O 4 ferrite nanospheres (NZFO) were successfully synthesized using an in situ polymerization method. The Ni 0.3 Zn 0.7 Fe 2 O 4 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/cm 3 was observed, thus illustrating the potential applications of the generated materials in microwave-absorbing fields.