▎ 摘　　要

Graphene (rGO) is a promising nano-filler for reinforcing the properties of polymer nanocomposites, but the aggregation in polymer nanocomposites limits its application. To solve this problems, rGO was functionalized with silicon-based organic/inorganic flame retardants through sol-gel process with controllable thicknesses (1.9 nm thick and 4.9 nm thick). The functionalized graphenes, noted as FGO-1 (1.9 nm thick) and FGO-2 (4.9 nm thick), are then incorporated into polyurea (PUA) at the loadings of 1 wt% and the property reinforcement are compared and investigated. After surface modification, covalent attachment of organic/inorganic flame retardants to the surface of rGO can prevent the agglomeration effectively and greatly improve the dispersion of rGO in the PUA matrix. Since those silicon-based flame retardants can act as a good compatibilizer during in situ polymerization process, and all the PUA/FGO composites have good dispersion at the loading of 1 wt%, as evinced by transmission electron microscopy result. When 1 wt% of FGO-2 is incorporated into PUA matrix, thermal and flame retardant properties of the composites are enhanced significantly compared with those of PUA/FGO-1 composites in air atmosphere. Moreover, the introduction of FGO-1 results in a 17.7% increase in tensile strength, while the PUA/FGO-2 results in 31.4% increase. The good dispersion and organic/inorganic flame retardants on the surface of rGO are believed to be key factors for the improvement of mechanical properties of PUA/FGO-2 composites. POLYM. COMPOS., 39:4637-4645, 2018. (c) 2017 Society of Plastics Engineers