Kevlar-functionalized graphene nanoribbon for polymer reinforcement

Multiwalled carbon nanotubes (MWCNTs) have been widely used as reinforcement fillers in past decades. However, the reinforcement effect has been greatly hindered by the limited available interface area (AIA) with polymer matrices for polymer composites. Successively, the method of oxidative unzipping MWCNTs into graphene nanoribbons (GNRs) was demonstrated to be the effective way for addressing the inherent drawback of MWCNTs. However, the GNRs are easy to agglomerate in polymer matrix even at relatively low loading amount. In this paper, we found that the functionalization of GNRs with Kevlar^® can significantly improve the dispersion state of GNRs in polymer matrix. Consequently, Kevlar^®-functionalized graphene nanoribbons (KGNRs) were successfully prepared through non-covalent functionalization of π–π stacking interaction between the aromatic area of Kevlar^® and the graphitic surface of GNRs. As-prepared KGNRs were characterized by FT-IR, TGA, XRD and TEM measurements. Poly(vinyl chloride) (PVC) and poly(methyl methacrylate) (PMMA) were selected as model polymers to investigate the reinforcement effect of KGNRs. The KGNRs could be well dispersed in PVC and PMMA matrices at relatively high loading level. Meantime, the ultimate tensile strengths and Young's modulus of KGNRs/PVC and KGNRs/PMMA composite films were significantly improved. Based on the observations above, KGNRs hold great promise in many potential applications in the future.