Ideal dielectric thermally conductive bismaleimide nanocomposites filled with polyhedral oligomeric silsesquioxane functionalized nanosized boron nitride

Silane coupling reagent γ-glycidoxy propyl trimethoxy silane/polyhedral oligomeric silsesquioxane (KH-560/POSS) functionalized nanosized boron nitride (POSS-g-nBN) fillers were performed to fabricate thermally conductive bismaleimide/diallylbisphenol A (BMI/DABA) nanocomposites combining excellent dielectric properties and outstanding thermal stability. POSS molecules have been grafted on the surface of the nBN fillers. The POSS-g-nBN/BMI/DABA nanocomposite with 15.4 vol% POSS-g-nBN is an excellent dielectric composite material with high thermal conductivity and outstanding thermal stability; the corresponding dielectric constant ϵ is 3.42, the dielectric loss factor tan δ is 0.0085, the thermally conductive coefficient λ is 0.607 W m^-1 K^-1 (increased by 266% compared to that of pure BMI/DABA), and the 5 wt% thermal weight loss temperature (T₅) reaches up to 428 °C, which holds potential for use in the integration and the miniaturization of microelectronic devices.