▎ 摘　　要

A rapid, green, and cost-effective route for the preparation of graphene nanosheets (GRNs) from their layered bulks by the ultrasonic together with mechanical grinding was reported. The whole exfoliation process of synthesizing GRNs lasted just 2 hours without involvement of any acid solvent or other organic solvents; only one kind of waste biomass as adhesive could be used. The structure and morphology of GRNs were characterized and then was then introduced into polypropylene by melt blending, and the cone calorimetry test results indicated that the presence of GRNs could enhance the flame retardancy of PP composite.