Curing and mechanical properties of nitrile and natural rubber blends

The curing and mechanical properties of nitrile (NBR) and natural rubber (NR) blends were carried out. Two series of blends were prepared, i.e., NBR/SMR L and NBR/ENR 50 blends. Blends were prepared using a Brabender at a temperature of 60degreesC. Results indicate that the scorch time, t(2) and cure time, t(90) increase with increasing NBR content in both blends, In NBR/ENR 50 blends the increasing content of NBR increases the maximum elastic torque, torque difference, tan delta @, MH and viscous torque. However, in NBR/SMR L blends the opposite trend is observed for maximum elastic torque and torque difference. In both blends modulus at 100% elongation (M100) and at 300% elongation (M300) increases with increasing NBR content, whereas tensile strength and elongation at break show a decreasing trend.