Improving the Mechanical Properties and Wear Resistance of Rubber/Graphene Composites Through Surface Modification of Carbon Black

ABSTRACT Carbon black (CB) was employed as a traditional reinforcing filler for rubber, and filler agglomeration was frequently encountered in rubber‐based composites, which was caused by inadequate interfacial compatibility. Improving the agglomeration and interfacial compatibility of CB to realize the effective enhancement of the overall performance of rubber composites is still the main challenge. In this study, environmentally friendly waterborne polyurethane (WPU) was introduced to functionalize the CB, and WPU encapsulated carbon black (ECB) core‐shell structures with multiple interfacial interactions were systematically constructed to solve the problem of CB agglomeration in NR composites. Due to the “physical coating‐hydrogen bonding‐chemical bonding” interfacial structure formed between the WPU molecules on the ECB surface and the NR molecular chains, the dispersibility of ECB fillers in NR and the interfacial interaction with NR molecular chains were significantly enhanced. Meanwhile, the excellent dispersibility of CB also promoted the synergistic effect of forming the “NR‐GO‐ECB” interfacial structure with graphene oxide (GO). Compared with the uncoated NR/GO/CB composites, the NR/GO/ECB composites exhibited superior mechanical properties and wear resistance, with their tensile strength, tear strength and wear resistance increased by 12.2%, 41.9% and 18.4% respectively. What's more, NR composite models were constructed by molecular dynamics simulation method, which systematically elucidated the enhancement mechanism of interfacial compatibility at the filler–matrix on the mechanical properties from the microscopic level. Hence, this work is anticipated to offer fresh insights into tailoring the interface between CB and NR, to introduce alternative routes toward green, energy‐efficient, and high‐performance rubber composites.