Experimental study and molecular dynamics simulation of dynamic properties and interfacial bonding characteristics of graphene/solution-polymerized styrene-butadiene rubber composites

Graphene/solution-polymerized styrene-butadiene rubber (SSBR) composites were prepared by using three types of SSBR matrix with different vinyl contents. The dynamic properties, interfacial bonding characteristics, and fractional free volume (FFV) of the composites were studied through a combined experimental and molecular dynamics (MD) simulation approach. We found that as the vinyl content increases in the SSBR matrix, the grapheme/SSBR interfacial interaction increases, the FFV decreases, and the graphene dispersion is improved. The interfacial interaction, which is derived from the introduction of graphene, can increase the activation energy and limit the mobility of the SSBR chains. Additionally, MD simulations of the pullout of the graphene from SSBR matrix were carried out to explore the interfacial bonding characteristics at the molecular level, which show that the interaction energy, pullout energy, and shear stress between graphene and SSBR increase with the increase of the vinyl content. The modeling results were in good agreement with the experimental results. This present study is expected to deepen the understanding of the basic physics for graphene reinforced rubber nanocomposites, especially the interfacial bonding characteristics at the molecular level.