Coordinated Control of the Properties of Rubber Composites Using a Dual‐Filler System

ABSTRACT Wet mixing and dry mixing are two entirely different mixing methods. Wet mixing can reduce the particle size of carbon black aggregates, whereas silica incorporated via dry mixing has larger aggregate sizes; through silane coupling agents, it can form a chemically cross‐linked network with the rubber matrix. This study aims to investigate the mechanism of synergy between fine‐particle wet‐modified carbon black and dry‐mixed silica, as well as the impact of the cross‐linking network formed between silica and the rubber matrix on material properties. This study investigated the effects of the ratio of fine‐particle‐size carbon black to coarse‐particle‐size silica on the filler network structure and filler–rubber interface interactions and determined the optimal ratio for achieving synergistic improvements in various properties. The results indicate that the Carbon black40/silica20 specimen exhibits the best overall performance. In this formulation, the high carbon black loading enables the formation of a continuous, rigid filler network, facilitating efficient stress transfer; an appropriate amount of silica reacts fully with the silane coupling agent to form a chemical cross‐linking network between the filler and the rubber, thereby fully leveraging the synergistic reinforcing effect of the biphasic filler system.