▎ 摘　　要

NOVELTY - Graphene oxide filler contains 100 pts. wt. graphene oxide modified with a flame retardant, and 20-1000 pts. wt. a compatibilizer, where the flame retardant and the compatibilizer are each combined with a functional group present on the surface or edge of the graphene oxide. USE - The filler is useful in flame retardant polypropylene composition (claimed). ADVANTAGE - The filler has: a flame retardant property; excellent compatibility with the base polymer, thus having excellent dispersibility; excellent tensile modulus and tensile strength; and excellent effect on improving the performance of a composite material is not limited to a filler for polypropylene and is expected to be applied in various fields e.g. automobile materials and building materials. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) preparing graphene oxide filler comprising (a) dispersing the graphene oxide on a solvent, and sonicating, (b) modifying the graphene oxide with a flame retardant by adding a flame retardant to the graphene oxide solution, and (c) mixing the graphene oxide modified with the flame retardant with a compatibilizer to introduce the compatibilizer to graphene oxide; and (2) flame retardant polypropylene composition comprising 76-98 wt.% polypropylene, and the 2-24 wt.% graphene oxide filler.