The invention relates to a
phosphorus-containing
fire retardant, a preparation method of the
phosphorus-containing
fire retardant and a
flame-retardant
epoxy resin prepared from the
phosphorus-containing
fire retardant, and especially relates to a phosphorus-containing
nitrile / DOPO double-base structure phosphorus-containing fire retardant, a preparation method of the phosphorus-containing
nitrile / DOPO double-base structure phosphorus-containing fire retardant, and
flame-retardant
epoxy resin prepared from the phosphorus-containing
nitrile / DOPO double-base structure phosphorus-containing fire retardant. The
flame-retardant
epoxy resin solves the problem that the existing epoxy resin has low flame retardation efficiency and poor compatibility between a
polymer matrix and a fire retardant. The preparation method comprises the following steps of 1, dissolving p-hydroxybenzaldehyde and
tetrahydrofuran, adding
triethylamine into the solution and carrying out stirring, 2, dissolving phosphonitrilic
chloride trimer in
tetrahydrofuran, dropwisely adding the solution into the
reaction system, and carrying out heating and stirring, 3, cooling the
reaction system, concentrating the filtrate, pouring the filtrate into water for precipitate separation, carrying out pumping
filtration, carrying out recrystallization on the precipitates and carrying out
drying to obtain intermediates, and 4, dissolving the intermediates by a
solvent, adding p-aminophenol into the solution, carrying out heating
reflux, adding DOPO into the
reflux product, carrying out condensation, pouring the concentrate into cold
ethanol for
solid precipitation, and washing and
drying the solids to obtain the phosphorus-containing nitrile / DOPO double-base structure phosphorus-containing fire retardant. The flame-retardant epoxy resin comprises epoxy resin, a curing agent and the phosphorus-containing nitrile / DOPO double-base structure phosphorus-containing fire retardant. The preparation method is used for preparing the phosphorus-containing nitrile / DOPO double-base structure phosphorus-containing fire retardant.