Study of dielectric property on BaTiO3/BADCy composite

The barium titanate (BaTiO3)/bisphenol A dicyanate (2,2′-bis(4-cyanatophenyl) isopropylidene) (BADCy) 0–3 dielectric composite was successfully prepared by casting. At 1 MHz and 298 K, the dielectric property of the composite was investigated systematically. The results showed that with the increase of the BaTiO3 content, the dielectric constant (ɛ) of the composite increased, while the dielectric loss (tan δ) decreased. When the mass fraction of BaTiO3 was 60%, ɛ reached its highest value (15.823) and tan δ was at its lowest (0.004). After post-curing at 230 °C for 4 h, tan δ dropped to 0.001. Meanwhile, with the increase of the conversion of BADCy, ɛ ascended at first and then descended slightly, but tan δ descended during the whole curing period. In addition, a silane coupling agent γ-aminopropyl triethoxy silane (KH-550) was applied to treat the filling so as to improve the dispersion of BaTiO3 particles, which led to enhance the dielectric property of the material.