A Study of The Effect of Carbon Black Powder on The Physical Properties of SBR/NR Blends Used In Passenger Tire Treads

The use of polymer blends is an effective method for altering the performance of polymer materials and is widely employed in engineering plastics, rubber, and fiber materials. Elastomeric blends are used for many reasons such as lowering the compound cost, for ease of fabrication and to improve the performance of the industrial rubber. In this study, 20 different rubber compounds were prepared by using SMR-20 type of natural rubber and SBR-1502 type of styrene–butadiene rubber in different levels (0, 25, 50, 75 and 100 pphr) and each recipe reinforced with carbon black at different ratio (20, 40, 60 and 80) pphr (part per hundred). The physical properties – such as thermal conductivity, thermal diffusivity, swelling and specific gravity were studied. The results show that the thermal conductivity and thermal diffusivity increased with increase of loading level of carbon black and these properties decreased with the increase of NR to SBR. The swelling property in this work measured by change in mass method by immersed the samples in oil and water. The swelling in water more than in oil, change in mass of the NR/SBR blends increased with immersing time increase and decreased with carbon black increment, and with the increment of NR percentages to SBR. The specific gravity increased with increase of carbon black loading for all recipes.