Graphene/Polystyrene Nanocomposites: Superior Electrical Conductivity And Rheology Behavior

Graphene has attracted enormous academic interest due to itsexceptional two-dimensional structure and electron transport, mechanicalproperties, and high surface area.When incorporated at very low fillercontent，it can significantly improve electrical,thermal,mechanical andgas barrier properties of polymers. However，preparation high-qualitygraphene and dispersion well in matrix remains a challenge.Nanoparticles in matrix tend to aggregation that can dominate rheological,viscoelastic of the nanocomposite. Study of basic physical relationshipsbetween nano-scale structural variables and properties of polymernanocomposites remains in its infancy.We firstly preparation the thermal expansion graphene and chemicalmodification graphenen by octadecylamine.and analysis spacing、different methods of preparation of, the groups containning oxygen andmorphology characterization.we report a facile approach to preparesuperior conductive graphene-polystyrene composites with styrene maleicanhydride copolymer (SMA) as compatibilizer by solution blending. Forcomparison, octadecylamine modified graphene (ODA-G) and thermallyreduced graphene were also used in material preparation. Scanning electron micrographs showed that the uniformly dispersed graphene wasencapsulated with a polymer layer with the presence of SMA, which isdistinct with the clean “pull out” feature of ODA-G and aggregated stateof graphene in matrix, indicating the strong interfacial interactionsbetween SMA mediated graphene and matrix. Rheological measurementsfurther confirmed the much better dispersion quality of SMA mediatedgraphene compared to ODA-G and unmodified graphene. As a result,SMA functionalized graphene composites exhibit a percolate threshold aslow as0.3vol.%and high electrical conductivities of31and85S/m for1.9and2.4vol.%of graphene, respectively. The superior conductivitymay be due to the high intrinsic electrical conductivity of thermallyreduced graphene and its perfect dispersion in polystyrene derived fromthe strong interactions of the residual oxygen functionalities on graphenewith the polar groups provided by SMA. The superior conductivecomposite has great potential for applications as promising EMI shieldingmaterial.This paper comprehensively discusses the relationship betweenelectric conductivity and rheological property in order to establishconnection between microstructure and macro-property ofnanocomposites， with the assistance of dielectric properties ofmaterials， we explore influence of annealing on the recovery ofmicrostructure that can provide a reference for preparation of the multi-functional materials with excellent properties.