The role of SEBS in tailoring the interface between the polymer matrix and exfoliated graphene nanoplatelets in hybrid composites

Nanocomposites of polypropylene (PP) and polypropylene/styrene-(ethylene-co-butylene)-styrene triblock copolymer (SEBS) blends with exfoliated graphene nanoplatelets (xGnP) were prepared by melt-mixing method. The incorporation of xGnP increased the stiffness and crystallinity of PP at the expense of toughness and the molecular mobility. The effect of addition of SEBS on the mechanical, viscoelastic, thermal degradation and crystallization properties of PP/xGnP composites was studied. The addition of SEBS into PP transformed the phase structure and distribution of xGnP in the PP matrix. SEM micrographs revealed that SEBS polymer chains formed a coating over the graphene nanoplatelets, which strengthened the interface between the filler and the matrix, and improved the dispersion and distribution of the filler throughout the matrix.