Study on calcium fluoride modified graphene/brominated butyl rubber nanocomposites

Graphene oxide (GO), NaF and CaCl₂ were mixed in their aqueous solutions to obtain a GO–CaF₂ hybrid with CaF₂ particles uniformly dispersed on GO surface, and further in situ reduced by hydrazine to obtain reduced-GO (RGO)-CaF₂ hybrid. RGO–CaF₂/brominated butyl rubber (BIIR) composites were obtained by solution mixing, in which RGO–CaF₂ was well dispersed in nano-sized as confirmed by transmission electron microscope images. The RGO–CaF₂/BIIR composites had much better mechanical properties than BIIR. The stress at 300% extension of BIIR increased 72% after the addition of 3 parts per hundreds of rubber (phr) RGO–CaF₂. The improved mechanical properties benefited from the strong interaction between RGO and BIIR. The dielectric constant of RGO–CaF₂/BIIR composites increased with increasing RGO–CaF₂ loading. Because of the synergistic effect of RGO and CaF₂, the stresses at various extensions, dielectric constant and thermal conductivity of RGO–CaF₂/BIIR composites were higher than those of RGO/BIIR or CaF₂/BIIR composites. The improved mechanical, dielectric and thermal properties bring BIIR the potential to be used in a wider range of application areas.