Largely enhanced fracture toughness of an immiscible polyamide 6/acrylonitrile–butadiene–styrene blend achieved by adding chemically modified graphene oxide

Abstract

In this work, chemically modified graphene oxide was successfully prepared by emulsion polymerization of styrene, leading to grafting polystyrene (PS) onto graphene oxide (GO). Different contents of polystyrene grafted graphene oxide (PS–GO) were incorporated into immiscible polyamide 6/acrylonitrile–butadiene–styrene (PA6/ABS) blend and it was expected that PS–GO could tune the morphology and improve mechanical property. The mechanical testing showed a great improvement on ductility of polymer blends, in which the elongation at break increased by nearly 400% and the impact strength increased by nearly 200% with only 0.5 wt% PS–GO. The underlying mechanism for toughening was carefully discussed via investigations on effects of PS–GO on morphology, chain mobility as well as interfacial interaction. The morphology changes of the blend with PS–GO show slight increase of continuity of ABS. The fracture morphologies showed that the addition of PS–GO induced enhanced interfacial adhesion, exhibiting finer fracture morphology. DMA results verified the enhanced interfacial interaction between ABS and PA6 with the addition of PS–GO. Furthermore, the results demonstrated the interface localization of PS–GO in PA6/ABS. Combined with these observations, it was suggested that the PS–GO located at interface of immiscible blends PA6/ABS and enhanced the interfacial adhesion via the dual interactions with two components, in which one was the electronic stacking interaction between grafted PS on PS–GO and ABS while the other one was the interaction between polar groups on PS–GO and PA6, finally resulting in a great improvement on ductility.