An unusual decrease in dielectric constant due to the addition of nickel hydroxide into silicone rubber

Materials with low dielectric constant have drawn more and more attention due to their wide range of applications in electronic devices. Two type of methods are often used to reduce the dielectric constant of a given materials: introducing voids and replacing groups having higher polarizability with the ones having lower through copolymerization . Different from above methods, current study proposes a novel and efficient method by allow inorganic filler participating the curing process of polymer matrix , thus, consuming some of the functional groups with high polarizability. Nickel hydroxide (Ni(OH) 2 ) is selected as filler to be dispersed in room temperature vulcanized silicone rubber (SR). The addition of 1% Ni(OH) 2 into SR has resulted a decrease in dielectric constant from 3.1 to 2.1, and slightly reduced dielectric loss. With further increasing Ni(OH) 2 content, the dielectric constant increases gradually. From various characterizations, it is confirmed that Ni(OH) 2 is involved in the curing process of SR, thus, the hydroxyl group content in the final composites is reduced. Meanwhile, Ni(OH) 2 with different size and synthesized Ni(OH) 2 from hydrothermal process is also used to further confirm such observation. This method provides a novel route for the preparation of low dielectric constant materials.