▎ 摘　　要

NOVELTY - A phosphaphenanthrene-based silane graft-modified graphene (I), is new. USE - New phosphaphenanthrene-based silane graft-modified graphene used as flame retardant. ADVANTAGE - The phosphaphenanthrene-based silane graft-modified graphene is efficiently manufactured at low cost, has intramolecular synergistic flame retardance of phosphaphenanthrene and graphene, phosphorus-silicon double-element synergistic effect of the phosphaphenanthrene and graphene synergistic flame retardant, phosphorus-silicon-sulfur three-element synergistic effect of the phosphaphenanthrene and graphene synergistic flame retardant, and excellent flame retardant performance. DETAILED DESCRIPTION - A phosphaphenanthrene-based silane graft-modified graphene of formula (I), is new. An INDEPENDENT CLAIM is included for manufacture of the phosphaphenanthrene-based silane graft-modified graphene (I), which involves (i) dissolving vinyltrimethoxysilane, azobisisobutyronitrile and 9,10-dihydrogen-9-oxygen-10-10-oxide in a solvent, stirring at 55-75° C, and cooling to room temperature to obtain a mixture, (ii) evaporating the mixture in step (i) for 0.8-1.5 hours, and drying at 85-95° C for 7-9 hours to obtain a light-yellow viscous liquid, (iii) adding 100-110 ml tetrahydrofuran to 50-60 g viscous liquid of step (ii), stirring, adding 28-30 ml acetic acid aqueous solution, heating to 55-62° C and stirring for 1-2 hours to obtain a hydrolyzed solution, and (iv) adding 200-210 ml tetrahydrofuran and 300-310 ml xylene to the hydrolyzed solution in step (iii), adding 50-52 g graphene oxide and reacting at 65-75° C for 20-24 hours, finally washing with ethanol, suction filtrating, and vacuum drying at 75-85° C for 11-13 hours. The mass ratio of vinyl trimethoxysilane, azobisisobutyronitrile to the 9,10-dihydrogen-9-oxygen-10-10-oxide is (14-15):(21-22):0.3.