▎ 摘　　要

NOVELTY - Preparing flame retardant additive, comprises making polymer (I) chelat with divalent zinc ions to form ligand, mixing the ligand with graphene oxide nanosheets and surface of graphene oxide nanosheets contains functional groups, and connecting ligand on the surface of the graphene oxide nanosheet by hydrogen bond and/or covalent bond to form intermediate, subjecting the intermediate to a reduction reaction to eliminate the functional groups freely present on the surface of the graphene oxide nanosheets in the intermediate. USE - The flame retardant additive is useful in fields of electronic devices, thermal management and construction. ADVANTAGE - The flame retardant additive: has improved thermal conductivity and flame retardancy of the composite material. DETAILED DESCRIPTION - Preparing flame retardant additive, comprises making polymer of formula (I) chelat with divalent zinc ions to form ligand, mixing the ligand with graphene oxide nanosheets and surface of graphene oxide nanosheets contains functional groups, and connecting ligand on the surface of the graphene oxide nanosheet by hydrogen bond and/or covalent bond to form intermediate, subjecting the intermediate to a reduction reaction to eliminate the functional groups freely present on the surface of the graphene oxide nanosheets in the intermediate. A = (hydroxyphosphoryl)yl or does not exist; and R1-R4= carboxy, sulfonic acid group or H. Provided that: R1, R-2 are not hydrogen at the same time; and R3, R4are not hydrogen at the same time. INDEPENDENT CLAIMS are included for: flame retardant additive prepared by above method; flame-retardant polymer composite material comprising a resin matrix and a flame retardant, where the flame retardant comprises the flame retardant additive.