Preparation and dielectric properties of PATP-coated nano-BaTiO3/epoxy resin composites

To achieve high-εr, low-tgσ polymer composites, a multistep grafting route was designed to coat BaTiO3 (BT) nanoparticles with polymer PATP and then composite them with epoxy resin. FTIR and TGA were used to evaluate the chemical grafting of BT nanoparticles. TEM and SEM were utilized to characterize the morphology and microstructure of samples. The effects of surface modification and filler fraction on dielectric properties were investigated. The results show BT nanoparticles were successfully encapsulated with a PATP shell of 5–10 nm, which not only improves the dispersion of BT nanoparticles in epoxy resin, but also suppresses the dielectric loss of composites. The obtained composites have high dielectric constant and very low dielectric loss, which can be tailored by surface modification of nano-BT and varying the filler fraction.