▎ 摘　　要

NOVELTY - Preparation of flame-retardant aqueous polyurethane involves preparing phosphazene-modified graphene, adding a polymer diol, ultrasonically dispersing, adding diisocyanate, chain extender and catalyst, reacting at 65-85 degrees C for 2-3 hours, adding a solvent, reacting to produce a prepolymer, adding deionized water to obtain reactive graphene-based aqueous flame-retardant polyurethane. The polyurethane contains 1-10 pts. wt. reactive graphene, 60-100 pts. wt. polymer diol, 30-50 pts. wt. diisocyanate, 5-20 pts. wt. solvent, 5-7 pts. wt. chain extender and 4-5 pts. wt. triethylamine. USE - Preparation of flame-retardant aqueous polyurethane for synthetic leather finishing, textile coating, paint and wood coating. ADVANTAGE - The aqueous polyurethane having excellent dispersion stability, emulsion stability, flame retardance, solvent resistance, abrasion resistance, aging resistance and water resistance is prepared. DETAILED DESCRIPTION - Preparation of flame-retardant aqueous polyurethane involves adding 2 g graphite powder and 1 g sodium nitrate to flask containing 50 ml concentrated sulfuric acid, stirring for 15 minutes, adding 6 g potassium permanganate powder, stirring at 0-10 degrees C for 15 minutes, maintaining at 35 degrees C for 30 minutes, adding 100 ml deionized water and 30% hydrogen peroxide solution to remove excess potassium permanganate, filtering, drying to produce graphene oxide, adding 0.5 g graphene oxide and 500 ml deionized water to flask, ultrasonically dispersing for 1 hour, adjusting pH to 8-10 by adding 5% sodium carbonate solution, adding 3-6 g reducing agent, stirring at 70-90 degrees C for 1-2 hours, cooling, filtering, washing with deionized, vacuum drying to produce reduced graphene powder, adding 0.5 g reduced graphene powder and organic solvent to flask, dispersing for 0.5-1 hour, adding 0.5-2 g acid-binding agent and 0.5-2 g chlorinating agent, reacting at room temperature for 1-2 hours, adding 0.9-3.3 g phosphorus-containing dihydric alcohol, reacting at 60-90 degrees C for 4-8 hours, cooling, filtering, washing and drying to produce reactive graphene modified with phosphazene compound, adding a polymer diol, ultrasonically dispersing, adding diisocyanate, small molecule diol chain extender and catalyst, reacting at 65-85 degrees C for 2-3 hours, adding a solvent, reacting to produce a prepolymer, adding deionized water under high shear force to obtain reactive graphene-based aqueous flame-retardant polyurethane. The polyurethane comprises 1-10 pts. wt. reactive graphene, 60-100 pts. wt. polymer diol, 30-50 pts. wt. diisocyanate, 2-5 pts. wt. small molecule diol chain extender, 0.01-0.2 pt. wt. catalyst, 5-20 pts. wt. solvent, 5-7 pts. wt. hydrophilic chain extender and 4-5 pts. wt. triethylamine.