Nanoporous and IPN structural composite material of cyanate ester modified by hollow silica and polyimide

Cyanate ester resin (CE), a high-performance and low dielectric materials, was modified with amino hollow silica (HSMs-NH2) and polyimide resin (PI) to form an IPN structure. Reducing the crosslinking density of the composite system and accompanying with its steric hindrance effect, PI increased the free volume of the composite material. The hollow structure introduced by HSMs-NH2 further enhanced a low dielectric property. IPN structure and HSMs-NH2 also significantly improved the impact toughness of HSMs-NH2/PI/CE composites. The bonding between the Si–O–Si and HSMs-NH2 offered an excellent heat resistance and as well surface bonding capability to matrix, which reduced the decomposition and effectively improved their thermal stability. Simultaneously, profited by the hydrophobicity of Si–O–Si, HSMs-NH2/PI/CE composite materials enabled to keep low dielectric properties in humid environments. [Display omitted] •A composite material with low dielectric constant, high toughness, high temperature resistance, and moisture resistance.•HSMs-NH2 as a lightweight nano filler has a large cavity structure.•The formation of IPN structure in CE by PI not only reduces the dielectric constant of CE, but also improves its toughness.•HSMs-NH2 improves dielectric properties, heat and moisture resistance of PI/CE composite.