Tailoring gas permeation and dielectric properties of bromobutyl rubber – Graphene oxide nanocomposites by inducing an ordered nanofiller microstructure

The spatial distribution of graphene oxide (GO) nanoplatelets in a bromobutyl rubber (BBR) matrix has been tailored by exploiting the rubber latex mixing process to confine nanoparticles among latex microspheres, thus obtaining a segregated arrangement. The gas transport properties and the dielectric behavior of these nanocomposites displaying a ‘segregated’ morphology have been compared, for different filler contents, to those of BBR/GO nanocomposites in which the nanoparticles are uniformly dispersed within the rubber matrix. Relevant qualitative and quantitative differences emerge from the comparison of the properties of the two families of GO-based samples. It has been found that the segregated morphology enables a significant enhancement of the barrier properties of pristine rubber already at low levels of nanofiller loading. In addition, an exceptionally low value of the electrical percolation threshold has been detected, which is more than one order of magnitude lower than in the case of uniform filler dispersion. These effects are a direct consequence of the assembly and confinement of nanoparticles among the rubber latex microspheres.