Enhancement of flame retardancy of rubber matrix using nanofillers. 
Natural rubber (NR) nanocomposites filled with carbon nanotubes (CNT) and organoclay (O-MMT) were prepared by melt mixing, and their vulcanization, mechanical, thermal and flammability properties were characterized.  The obtained results were compared with those of carbon black (CB) and pure NR composites.  The incorporation of OC reduced drastically the cure times, when compared with CNT and CB-reinforced compounds.  The addition of CNT increased considerably the difference between minimum and maximum torques compared with OC and CB-reinforced composites.  The mechanical properties were improved by adding nanofillers of CNT and OC.  The nanocomposites filled with OC and CNT showed lower peak heat release rate (PHRR) obtained from a cone calorimeter and corresponding reduced surface cracks of formed chars after burning.  A slight synergistic effect was found for NR nanocomposite having equal amount of OC and CNT.