Surface Energy Distribution of Modified Carbon Black and Interfacial Interactions of Filled Rubber Composites

Carbon black (CB) modification to achieve both homogeneous dispersion and strong interfacial interactions is a challenging subject for high-performance tread rubber composites. The effect of modification on CB surface characteristics is difficult to analyze experimentally, resulting in an uncomprehensive knowledge of the factors influencing interfacial interactions. In this study, 4,4′-diaminodiphenyldisulfide (APDS) was utilized to modify CB. Through molecular simulation techniques, the interfacial binding energy and surface energy distribution were obtained to analyze the interfacial interaction and determine the influence of modifiers on strong binding sites on the CB surface. The strong binding sites were preserved, and the overall interaction was enhanced. The experimental results demonstrated that CB dispersion was evidently improved, and strong interfacial interactions were effectively maintained, verifying the results of molecular simulation. This study elucidated the critical effect of strong binding sites on the CB surface regarding interfacial interactions and also provided theoretical guidance for CB modification. The method of calculating the surface energy distribution of fillers by molecular simulation provides a new efficient strategy for interfacial characterization and modifier evaluation.