ABSTRACT
A variety of recent studies have demonstrated the effectiveness of graphene as a nano-filler material for rubber, leading to outstanding enhancements in its mechanical properties. This chapter reviews the critical reinforcement mechanisms that help explain these enhancements and allow an improved understanding of the governing structure-property relationships (SPRs) for rubber-graphene nanocomposites. We discuss with special emphasis, the key role of graphene-rubber interfacial interactions and the filler morphology at various length scales. We describe various reinforcement mechanisms of graphene such as mechanical interlocking, adhesion, strain-induced crystallization, local alterations to rubber chain dynamics, formation of glassy interphases, various length scale-dependent toughening mechanisms, as well as alterations to the kinetics of the vulcanization reaction in rubber. We then review various effective functionalization strategies aimed to improve the filler dispersion, as well as various important structural studies aimed at a fundamental characterization and understanding of the foregoing mechanisms. Despite many experimental studies, we observe that the development of mechanism-based constitutive models that incorporate the SPRs remains to be a rich area of research. To conclude, we underscore the impressive potential of graphene as a nano-filler for rubber and the importance of understanding the governing SPRs to realize its full benefits.
