Effect of POSS as compatibilizing agent on structure and dielectric response of LDPE/TiO2 nanocomposites

Two types of nanocomposites were prepared. The first type was prepared by ball milling-blending of untreated titanium dioxide (TiO₂) nanoparticles into low density polyethylene (LDPE). For the second type, a commercial chemically treated TiO₂ with trisilanol phenyl polyhedral oligomeric silsesquioxane (TSP-POSS) as dispersant was ball milling-blended into LDPE. In this paper, titanium dioxide was selected as a model to show the effect of POSS on dispersion improvement of metal oxides nanoparticles and to understand the correlation between structure and dielectric response of LDPE/TiO₂ nanocomposites. The microscopic observation by AFM showed that the TiO₂ treated with the POSS were better dispersed in the polymer matrix as compared to untreated TiO₂. Furthermore, the dielectric loss for the nanocomposites filled with treated TiO₂ was significantly lower than that for nanocomposites filled with untreated TiO₂ nanoparticles.