Figure 4 shows the hardness and resilience of the NR/PP blends as a function of filler loading. It can be seen that hardness increase with increasing carbon black loading. In other word, the resilience of carbon black filled NR/PP blends decrease with increasing
carbon black loading. It inferred that carbon black could restrict the mobility and deformability of the matrix macromolecules at higher degree with increasing carbon black loading [5].