▎ 摘　　要

NOVELTY - Method comprises (i) dissolving terephthalaldehyde in ethanol solvent, using magnetic stirrer under the heating condition, rotating at constant speed, dissolving terephthalaldehyde in ethanol solvent, mixing diethylenetriamine and triethylene tetramine solution, mixing, dripping into terephthalaldehyde/ethanol solution, rotating at constant speed gradually separated out yellow solid, introducing yellow solid obtained by reaction in absolute ethyl alcohol for ultrasonic cleaning, removing the unreacted component, introducing yellow solid into an oven for drying, removing the solution, (ii) introducing in an oven to bake for 5 hours, (iii) taking nanosheet graphene as reinforcing phase, introducing polyimide substrate powder, grinding and mixing the mixed powder by ball mill to obtain the composite material powder, where the adding amount of the nano-sheet graphene is 0.5-2 wt.%; (iv) introducing composite material powder in the mold, and hot pressing the mold. USE - The nano-sheet graphene-reinforced polyimine composite material is useful in preparing engineering plastic (claimed). ADVANTAGE - The method is simple, from hardness, tensile strength, bending strength, impact strength and improves the mechanical performance of the polyimide substrate and realizes recycling use.