Effect of acid-base characteristics of carbon black surfaces on mechanical behaviors of EPDM matrix composites

The effect of acid-base treatments of carbon blacks (CBs) was investigated in the mechanical properties of CBs/rubber composites. The surface characteristics of the CBs were determined by the pH, acid-base values, and surface energetics. Their mechanical properties of the composites were also evaluated by the crosslink density (V_e) and tearing energy (T). As an experimental result, acidically treated CBs led to the increase of the specific component (γ_S^SP), resulting in decreasing the mechanical properties of the composites. However, basically treated CBs showed a higher value of the dispersive component (γ_S^L) than that of the untreated or acidically treated CBs. It was also found that the interaction of the CBs-rubber was improved, resulting in the improvement of the crosslink density and mechanical properties of the composites. It was then remarked that the acid-base characteristics of the CB surfaces made an important role in improving the physical properties of the rubber matrix composites.