Preparation of GNP/SBR thermal conductivity composites with high strength and toughness by synergistic construction of interfacial multiple non‐covalent and covalent bonds

Abstract [AMIm]Cl@GNP/SBR composites were prepared by blending ionic liquid 1‐allyl‐3‐methylimidazolium chloride salt([AMIm]Cl) modified graphene nanoplatelets (GNP) and styrene‐butadiene rubber (SBR). The mechanical and thermal properties as well as the structure–activity relationship of the obtained composites based on the modified filler were investigated under the synergistic effect of non‐covalent and covalent bonding. The experimental results indicated that the modification of GNP by [AMIm]Cl occurred under mild conditions. The dispersibility of [AMIm]Cl@GNP in SBR was enhanced by its participation in vulcanization and the synergistic effect of non‐covalent and covalent cross‐linking networks such as cation‐π, π‐π, and hydrogen bonds. This improvement led to an increase in the interfacial bond strength of the composites and a reduction in the interfacial thermal resistance. These effects resulted in both reinforcement and thermal conductivity properties. The tensile strength and elongation at break of [AMIm]Cl@GNP/SBR composites increased from 18.2 to 22.9 MPa and from 737.9% to 923.5%, respectively, when the modification ratio of [AMIm]Cl was 1% and the loading of [AMIm]Cl@GNP was only 4 phr (mass ratio). At the same time, the thermal conductivity in the vertical direction of the composites increased from 0.25 to 0.44 W/(m·K), and the thermal conductivity in the horizontal direction increased from 0.27 to 0.81 W/(m·K). Highlights Modified powder [AMIm]Cl@graphene nanoplatelets were prepared; [AMIm]Cl@graphene nanoplatelet/styrene‐butadiene rubber blend was prepared; Mechanical properties of blends significantly improved over blank; The horizontal thermal conductivity of the blends increases obviously; The vertical thermal conductivity of the blends was improved.