▎ 摘　　要

NOVELTY - The preparation of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide composite flame retardant involves adding tetrahydrofuran dispersion system of graphene oxide and a tetrahydrofuran solution system of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, mixing dispersion liquid system and obtained solution system, carrying out grafting reaction in protective atmosphere. USE - Preparation of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide composite flame retardant (claimed). ADVANTAGE - The method enables preparation of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide composite flame retardant with high flame retardant effect and wide application range by simple and easy process.