Graphene can be utilized as an additive to produce composites with outstanding properties by improving the stabilization of the morphology of bicontinuous blends. The bicontinuous structure can be used to create novel porous materials and reduce the percolation threshold when graphene is selectively localized at the interface or preferentially in a single phase. This study explores the effect of reactive graphene on the immiscible polystyrene/polylactic acid (PS/PLA) system. Transmission electron microscopy and scanning electron microscopy observations showed that the reactive graphene can be selectively localized at the interface of the PS/PLA system, stopping the coarsening of the structure during static annealing and stabilizing the morphology. Dynamic rheological measurements showed that the addition of reactive graphene had a significant effect on the elastic properties of the blend. Moreover, it was shown that reactive graphene can form a percolated conductive network, which also showed a significant recovery upon destroying the initial microstructure.