Electrical conductivity and mechanical properties of ionic liquid modified shear exfoliation graphene/CO‐PA nanocomposites at extremely low graphene loading

In this study, the ionic liquid (IL) modified shear exfoliation graphene (SEG)/co‐polyamide (IL‐SEG/CO‐PA) nanocomposites were fabricated by an effective and simple solution mixing method. In detail, SEG was fabricated in aqueous phase and then modified by IL, 1‐butyl‐3‐methylimidazolium chloride (BMIMCL) to enhance its dispersion in CO‐PA matrix. The IL‐SEG/CO‐PA nanocomposites were of good properties, such as thermal property, electrical conductivity and mechanical properties, especially a low percolation threshold of not higher than 0.15 wt% (about 0.0523 vol%). The tests and measurements indicated that the Tc, T_−50%, and T_d‐max of the nanocomposites was 17°C, 18°C, and 22.5°C higher than that of CO‐PA respectively; when SEG content was 0.75 wt%, the electrical conductivity was improved from 2.85 × 10⁻¹² S/m to 1.32 × 10⁻⁷ S/m, the tensile strength increased by 43.2%, and yield strength 19.7%. The incorporation of IL resulted in the good exfoliation and dispersion of graphene in CO‐PA matrix, which could be the direct reason for the improvement of the nanocomposites. POLYM. COMPOS., 38:E277–E284, 2017. © 2016 Society of Plastics Engineers