Abstract: A compound (PAPDO) containing phosphorus and nitrogen was synthesized from 9, 10-dihydro-9-oxa-10vphosphozaphene-10-oxide (DOPO), 3, 4-dihydroxybenzaldehyde and p-phenylenediamine in a one-pot method. A hybrid flame retardant (ZnPA@PAPDO) was prepared by coating PAPDO on zinc phytate using the force between the phenol hydroxyl group of protoca-techualdehyde and metal ions. EP/ZnPA@PAPDO was prepared with ZnPA@PAPDO as the flame retardant, epoxy resin (EP) as the base material and diaminobenzene methane (DDM) as the epoxy curing agent. The effect of ZnPA@PAPDO on the flame retardant property of EP was studied. Thermogravimetric results showed that the addition of ZnPA @ PAPDO advanced the initial decomposition temperature of the composite, promoted the charring of the polymer and formed a char layer on the surface to effectively protect the matrix. The addition of ZnPA@PAPDO can increase the residual amount at high temperature, and the residual amount of EP/8% ZnPA@ APDO increased by 31.0%. In addition, the addition of ZnPA@PAPDO greatly improved the flame retardant property of EP. The t1+t2 of EP/8% ZnPA@PAPDO is 11.6 s, reaching V-1 level, and the LOI value is 32.8%. The excellent thermal and flame retardant properties of EP/ZnPA@PAPDO are attributed to the double barrier action of organic coke and metal protective layer, phosphorous nitrogen synergism and free radical quenching.

Key words:  epoxy resin, flame retardant property, DOPO, nano hybridization