Nano-silicon carbide/carbon black hybrid fillers for accelerating the curing of styrene-butadiene/butadiene rubber blend by improving thermal diffusivity

The synergistic impact of combining nano-silicon carbide (SiC) and carbon black (CB) on enhancing the cure characteristics and vulcanization reaction of the styrene-butadiene/butadiene rubber blend is investigated by promoting thermal diffusivity. The oscillating disk rheometer (ODR) results indicated a ~ 3%, ~ 23% and ~ 15% reduction in both scorch and curing times, and the time differences between them due to SiC. Furthermore, SiC induced a notable 3% increase in the minimum torque and a substantial 39% increase in the maximum torque during the ODR test. The curing features improved with SiC content, particularly at 12 phr. However, the 30 phr of CB decreased the scorch time by ~ 10%, and enhanced the minimum and maximum torques by ~ 4% and ~ 12%, respectively. The Kamal-Sourour autocatalytic model applied on the rheometry data exhibited a ~ 100% acceleration in the curing reaction rate by 12 phr SiC. This study monitored temperature variations in the sample during both thermalization within the curing and subsequent natural cooling using a specialized setup, aiming to elucidate the effect of the fillers on the curing reaction mechanism. The results illustrated an increase in the heat transfer within the samples by ~ 30% at 12 phr SiC and 30 phr CB. Nevertheless, 30 phr of CB enhanced the thermal diffusivity of the rubber blend by ~ 250%.

Graphical abstract