Curing epoxy with polyethylene glycol (PEG) surface-functionalized NixFe3-xO4magnetic nanoparticles

Abstract Properties of thermoset nanocomposites are dependent on cross-link density of resin network. Surface modification was known as the main solution to nanoparticle aggregation problem. Although surface modification can assist in reaction between curing moieties, tuning cross-link density of network remains as a challenge for desired properties. In this work, naked, polyethylene glycol (PEG)-capped (surface modified) and Ni2+-doped PEG-capped (surface-bulk modified) magnetic iron oxide (MIO) nanoparticles were synthesized via cathodic electrodeposition, and then characterized by X-ray diffraction, field-emission scanning electron microscopy, vibrating sample magnetometry and Fourier transform infrared spectroscopy. Low filled epoxy nanocomposites containing 0.1 wt.% of three aforementioned MIOs were prepared and underwent dynamic differential scanning calorimetry (DSC). The quality of cure of nanocomposites was studied by Cure Index criterion. Appling different heating rates in DSC analyses uncovered the role of bulk and surface-bulk treatment of MIO, by which firs steps were taken toward development of epoxy nanocomposites with tunable cross-link density.