Method for preparing modified cellulose fire-retardant fiber through reaction extrusion

The invention discloses a method for preparing a modified cellulose fire-retardant fiber through reaction extrusion, and the method comprises the following steps of: 1. preparing a fire retardant, cellulose, a solvent and an acid-binding agent into a mixture according to a certain mass ratio, wherein the fire retardant is a novel phosphorus-based fire retardant, the cellulose is one of wood pulp, cotton pulp or bamboo pulp, the solvent is ion liquid, the acid-binding agent is potassium carbonate, the proportion is as follows: the mass ratio of the acid-binding agent to the fire retardant is 0.1-0.5:1, the mass ratio of the fire retardant to the cellulose is 0.5-2:1, and the mass ratio of the cellulose to the solvent is 10-25:90-75; 2. feeding the mixture into a double-screw extruder, and synchronously carrying out dissolution, reaction and extrusion of the cellulose through a reaction extrusion method to obtain the freshly formed filament of modified cellulose; and 3. stretching, washing, thermoforming and curling the freshly formed filament to prepare the modified cellulose fire-retardant fiber. The modified cellulose fire-retardant fiber obtained through the method disclosed by the invention has the advantages of no halogen, environmental friendliness without pollution and outstanding flame-retardant effect.