Influence of carbon black on cure properties and mechanical strength of natural rubber/butadiene rubber blends

In the present study rubber/rubber blends [RRB] of natural rubber [NR] and butadiene rubber [BR] with 50phr of carbon black [CB] in different blend ratios (70:30, 50:50, and 30:70) were prepared on a two-roll mill. Cure properties, density, morphology, and mechanical strength of CB filled NR/BR blends were analyzed. It was observed that the addition of CB improved the processing properties. A decrease in cure time in the presence of CB was observed. CB forms physical dense networks in filled RRB and increases the crosslink density as compared to the corresponding neat RRB. In addition to the improvement in processing properties, the addition of CB strengthens the interphase region within RRB thereby increasing the mechanical strength of the RRB. A correlation between the morphology driven CB partitioning within NR/BR blend would be informative to readers.