Synthesis, Characterization And Flame Retardant Research Of Derivatives Of Phosphaphenanthrene

9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) is a new organic phosphorus flame retardant intermediate, and its derivatives have the advanages of smoke-free, non-toxic, efficient and environmently friendly. In this paper, DOPO as the intermediates, which reacted with formaldehyde and benzoquinone, and then with different acyl chlorides. And two series of phosphaphenanthrene derivatives were synthesized. The structures of final compounds were characterized by1HNMR、13CNMR、31PNMR、FT-IRs HRMS、 ESI-MS. The reactivity of different substituents of substrates were discussed, and the reaction conditions were optimized. The fluorescence spertra and fluorescence intensity of compounds were studied, and the results displayed that the derivatives of DOPO have obvious aggregation-induced emission enhancement property. The thermal stability of the target compounds were characterized by TGA and DSC, the results indicated that the products have good thermal stability. The cyclic voltammetry curves of compounds displayed that they have excellent electrochemical stability. In addition, the flame retardant property of target compounds in lithium-ion battery were studied. The combustion experiments of the lithium-ion battery electrolyte which were added the target compounds were employed, the self-extinguishing time, flame propagation, fuel consumption rate and the conductivity of the electrolyte were tested, and the results indicated that the derivatives of DOPO have obvious flame retardant effect in the lithium-ion battery.