It can be observed from Table 1, that the adding of 10 wt % of NR to PP induces a decrease of the
maximal tensile strength, shore A hardness and it induces also an increase of the elongation at break. So,
the incorporation of NR to PP induces a decrease of the stiffness, strength and improves the ductility of
the resulting blend. These results can be explained by the soft nature of the NR when it is added to the PP
more rigid phase [17]. Moreover the 3 wt % organoclay based composite has the highest tensile
strength, hardness, elongation at break and impact strength (toughness). A maximal tensile strength for a
certain nanofiller concentration was observed in nanocomposite systems [22-25]. A maximal tensile
strength and a maximal elongation at break for a certain nanofiller concentration was also observed in a
nanocomposite system [26]. The existence of organoclay agglomerates is believed to reduce the tensile
elongation, this is because the agglomeration of the organoclay can act as a stress concentration point and
consequently increase the ability of the composite to initiate cracks [27].