▎ 摘　　要

NOVELTY - Preparing graphene modified APP/PERM/EL aqueous polyurethane flame retardant coating comprises e.g. (i) taking polycarbonate diol, polytetrahydrofuran ether diol, polyether diol, isophorone diisocyanate, dimethylol propionic acid, 1,6-hexanediol, trimethylolpropane and dibutyltin silicate, vacuum drying and dehydrating, taking acetone, triethylamine and drying, (ii) homogeneously mixing, stirring, cooling, adding, stirring and dispersing, (iii) mixing, ultrasonically dispersing and centrifuging, (iv) centrifuging and removing the solvent by distillation under reduced pressure. USE - The method is useful for preparing graphene modified APP/PERM/EL aqueous polyurethane flame retardant coating (claimed). ADVANTAGE - The method: has good thermal stability and good flame retardance. DETAILED DESCRIPTION - Preparing graphene modified APP/PERM/EL aqueous polyurethane flame retardant coating comprises (i) taking polycarbonate diol having molecular weight of 1000-2000, polytetrahydrofuran ether diol having molecular weight of 1000-2000, polyether diol having molecular weight of 1000-2000, isophorone diisocyanate, dimethylol propionic acid, 1,6-hexanediol, trimethylolpropane and dibutyltin silicate, vacuum drying and dehydrating, taking N-methyl-2-pyrrolidone, acetone, triethylamine and drying, (ii) taking 3-4 pts. wt. polycarbonate diol, 0.8-1.2 pts. wt. polytetrahydrofuran ether diol, 1-1.5 pts. wt. polyether diol and 9-10 pts. wt. isophorone diisocyanate, homogeneously mixing, stirring at 80-100 degrees C for 1.5-3 hours, cooling at 40-50 degrees C, adding 0.8-1 pts. wt. dimethylol propionic acid, 2-2.5 pts. wt. 1,6-hexanediol, 0.5-0.6 pts. wt. trimethylolpropane, 0.03-0.04 pts. wt. dibutyltin silicate in february, 100-200 pts. wt. N-methyl-2-pyrrolidone and 0-40 pts. wt. acetone, raising the reaction temperature at 75-90 degrees C for 2-3.5 hours, cooling at 20-30 degrees C, adding 0.6-1 pts. wt. triethylamine, stirring and dispersing for 1-1.5 hours to obtain aqueous polyurethane emulsion, (iii) mixing polyphosphate, pentaerythritol and melamine in a mass ratio of 1-3:1-3:1-2, adding aqueous dispersion of grapheneto the mixture, ultrasonically dispersing for 5-7 hours, centrifuging at 7000-8000 rotations/minutes (rpm) 8-12 minutes to obtain expansion flame retardant system of modification, where the mass ratio of the mixed liquid and graphene is 95-99:1-5, (iv) adding according to the mass ratio of 28-30:10-12:29-31:29-31 into a aqueous polyurethane emulsion, adding modified flammable flame retardant system, deionized water and anhydrous ethanol at room temperature, centrifuging at 5000-6000 rpm for 1-2 minutes and removing the solvent by distillation under reduced pressure to obtain graphene modified APP/PERM/EL aqueous polyurethane flame retardant coating, where the APP is ammonium polyphosphate, PERM is is pentaerythritol and EL is melamine.