Novel environmentally friendly waterborne polyurethane/hollow Ni0.3Zn0.5Fe2O4 nanocomposite films: superior magnetic and mechanical properties

Superparamagnetic nanocomposite films based on waterborne polyurethane and hollow Ni0.3Zn0.5Fe2O4 nanospheres (WPU/h-NZFO) were synthesized via an in situ polymerization technique. The h-NZFO nanoparticles were functionalized by vinyltriethoxysilane (VTES) to facilitate the dispersion and compatibility with the WPU matrix. The modified h-NZFO (h-NZFO-VTES), combined with the polymers through covalent bonds during the UV-curing process, acted as an effective cross-linker. The morphology, microstructure, thermal behavior, solvent resistance, mechanical and magnetic properties of the WPU/h-NZFO nanocomposites were investigated. It was found that functionalized h-NZFO nanoparticles could largely promote the emulsion stability, thermal stability, solvent resistance, mechanical and magnetic properties of WPU polymers. Importantly, the resulting WPU/h-NZFO films possess superior magnetic (24.2 emu cm−3) and mechanical properties, providing a promising route to prepare environmentally friendly WPU-based nanocomposites with high performance for practical applications, especially in microwave absorption fields.