Preparation and characterization of flexible polyurethane foam nanocomposites reinforced by magnetic core-shell Fe^sub 3^O^sub 4^@APTS nanoparticles

Novel magnetic polyurethane flexible foam nanocomposites were synthesized by incorporation of aminopropyltriethoxysilane (APTS) functionalized magnetite nanoparticles (MNPs) via one-shot method. The functionalized MNPs (Fe^sub 3^O^sub 4^@APTS) were synthesized by co-precipitation of the Fe^sup 2+^ and Fe^sup 3+^ with NH^sub 4^OH and further functionalization with APTS onto the surface of MNPs by sol-gel method. The magnetic core-shell NPs were used up to 3.0 % in the foam formulation and the magnetic nanocomposites prepared successfully. The results of thermogravimetric analysis (TGA) showed an increasing in thermal stability of polyurethane nanocomposite foam at initial, 5 and 10 %, and maximum thermal decomposition temperatures by incorporation of Fe^sub 3^O^sub 4^@APTS. In addition SEM images revealed the uniformity of the foam structures and decreasing in pore sizes. Furthermore, VSM result showed super paramagnetic behavior for Fe^sub 3^O^sub 4^@APTS-PU nanocomposites.