Poly(e-caprolactone)-Grafted Fe3O4 Nanoparticles: Preparation and Superparamagnetic Nanocomposites with Epoxy Thermosets

Poly(e-caprolactone)-grafted magnetic iron oxide nanoparticles (Fe3O4 NPs) were prepared via a surface-initiated ring opening polymerization approach. First, the surface of the unmodified Fe3O4 NPs were treated with 3-aminopropyltriethoxysilane to afford the 3-aminopropyl-functionalzed Fe3O4 NPs. Second, the surface-initiated ring-opening polymerization of e-caprolactone was carried out with the surface-functionalized Fe3O4 NPs as the initiator to afford the poly(e-caprolactone)(PCL)-grafted Fe3O4 NPs. The PCL-grafted Fe3O4 NPs have been characterized by means of Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, and transmission electron microscopy. It was found that the PCL-grafted Fe3O4 NPs can be well dispersed into epoxy thermosets. The nanocomposites were successfully obtained with the content of the PCL-grafted Fe3O4 NPs up to 40 wt %. The fine dispersion of Fe3O4 nanoparticles in epoxy was demonstrated by transmission electron microscopy and dynamic mechanical thermal analysis. The results of magnetic analysis with vibrating sample measuring technology indicated that the nanocomposites involving epoxy resins and Fe3O4 nanoparticles possessed superparamagnetic properties.