Acrylonitrile rubber (NBR) composites filled with barium titanate (BT) were prepared using an internal mixer and a two-roll mill.Also,a secondary filler,namely carbon nanotubes (CNT),was added in order to find a potential synergistic blend ratio of BT and CNT.The cure characteristics,tensile and dielectric properties (dielectric constant and dielectric loss) of the composites were determined.It was found that NBR/BT composites with CNT secondary filler,at a proper BT:CNT ratio,exhibited shorter scorch time (ts1) and cure time (tc90) together with superior tensile properties and reinforcement efficiency,relative to the one with only the primary filler.In addition,the NBR/BT-CNT composite with 80 phr BT and 1-2 phr CNT had dielectric constant of 100-500,dielectric loss of 12-100 and electrical conductivity below 10-4 S/m together with high thermal stability.Thus,with a proper BT:CNT mix and filler loading,we can produce mechanically superior rubber composites that are easy to process and low-cost,for flexible dielectric materials application.