without any reductions of ultimate
tensile strength and elongation at break. The BFA filler was
observed to be more compatible with the PSi than with the CB filler.
It is recommended for future works to investigate other related
factors that could enhance the mechanical properties of the hybrid
filler vulcanizates or increase the loading of the BFA content, such
as, effects of chemical and physical treatments on the filler surface,
and the particle size distributions of the BFA filler used.