Impulse Breakdown Strength of Epoxy/TiO2 Nanocomposite Enhanced by Agglomerate Removal

Agglomerates of nanoparticles, which inevitably occur during the fabrication process of epoxy nanocomposites, can affect the insulation properties of the epoxy nanocomposites. This study presents an attempt to clarify the effect of the agglomerate size on the impulse breakdown strength of epoxy/TiO
₂
nanocomposites. In particular, we changed the process conditions of the particle dispersion method using centrifugation to control the agglomerate size of several epoxy/TiO
₂
nanocomposite samples. The experimental results clarified that centrifugation can be effective for controlling the agglomerate size of epoxy/TiO
₂
nanocomposites. In addition, we examined the impulse breakdown strength of the epoxy/TiO
₂
nanocomposites whose agglomerate sizes were 0.5-50 μm. The impulse breakdown strength of the epoxy/TiO
₂
nanocomposites increased with a decrease in the agglomerate size. Finally, we determined the critical size of the agglomerates required for obtaining the epoxy/TiO
₂
nanocomposites with a higher breakdown strength when compared with that of an unfilled epoxy resin.