Preparation of ionic liquid modified graphene and its effect on enhancing the properties of PA6 composites

Abstract In this study, an ionic liquid (IL) with imidazole and amide groups has been prepared, and used to modify graphene (TSG) by ball milling to fabricate ionic liquid functional graphene (TSG‐IL). During the melt blending process, TSG‐IL forms hydrogen bond with the amide group of PA6, which destroys the hydrogen bond of PA6 itself, enhances the interfacial force between TSG‐IL and PA6 matrix, and improves the dispersion of TSG‐IL in PA6 matrix. There has been some improvement in the mechanical and thermal conductivity of PA6 composites. Additionally, the presence of amide groups makes it easy to form hydrogen bonds between TSG‐IL sheets, thus strengthening the connection between TSG‐IL and each other, which is conducive to the construction of thermal conductivity network. The findings indicate that compares to TSG/PA6 composites with the same filler amount, the TSG‐IL/PA6 composites have better heat conductivity and higher mechanical characteristics. 9 wt.% TSG‐IL/PA6 composite has the highest thermal conductivity (0.498 W·m⁻¹·k⁻¹), which is 92.3% and 17.2% greater than that of pure PA6 and 9 wt.% TSG/PA6, and its impact strength (11.12 kJ/m²) is 11.0% and 7% higher, which would be a popular candidate material in the field of thermal conductivity. Highlights Imidazole ionic liquids with amide groups was synthesized. Amide groups were modified onto graphene sheets by ball‐milling. The dispersion of TSG‐IL in PA6 was studied. Improved mechanical property and thermal conductivity of TSG‐IL/PA6 composites.