Simultaneous improvement in the strength and toughness of polypropylene by incorporating hybrid graphene/CaCO3 reinforcement

The effects of CaCO3 and graphene nanoplatelet (xGnP) as reinforcing fillers on the mechanical and thermal properties of polypropylene were investigated. The nanocomposite samples were fabricated by melt blending and hot-press processing. Maleic anhydride grafted polypropylene (MAPP) was used as a coupling agent for modifying the matrix. The amount of CaCO3 was kept constant at 15 wt % and the amount of xGnP was varied up to 1.5 wt %. Results showed that the synergy of CaCO3-xGnP reinforcements provided better mechanical properties for polypropylene than each individual filler. Also, the morphology and crystallinity of the nanocomposites were characterized using scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). Finally, the optimal xGnP content was found to be 0.75 wt % for effectively improving the overall nanocomposite mechanical performance.