▎ 摘　　要

NOVELTY - The preparation of polyurethane involves (1) adding macromolecular polyol to reactor, distilling, adding polyisocyanate and catalyst, reacting, (2) cooling, adding alcohol chain extender and hydrophilic chain extender, heating, (3) cooling, adding solvent and salt-forming agent, reacting to obtain prepolymer, (4) diluting graphene with isopropyl alcohol, mixing with silane coupling agent, stirring to obtain modified graphene, (5) adding prepolymer into modified graphene, adding water and small molecular amine chain extender, dispersing, and removing solvent. USE - Preparation of graphene-modified aqueous polyurethane for vehicle coating, wood, construction, office furniture and leather. ADVANTAGE - The method enables preparation of graphene-modified aqueous polyurethane with excellent hardness, flexibility, compactness, impact resistance, corrosion resistance, water resistance, aging resistance, and stain resistance. DETAILED DESCRIPTION - The preparation of aqueous polyurethane involves (1) adding macromolecular polyol to reactor, vacuum distilling at 95-105 degrees C for 30-60 minutes until the water content is less than 0.5%, cooling to 55-65 degrees C, adding polyisocyanate and catalyst, heating at 70-90 degrees C, reacting for 2-4 hours, (2) cooling to 55-65 degrees C, adding small molecule alcohol chain extender and small molecule hydrophilic chain extender, heating at 70-90 degrees C for 2-4 hours, (3) cooling to 40-60 degrees C, adding solvent to reduce viscosity, adding salt-forming agent, reacting for 15-30 minutes to obtain prepolymer of aqueous polyurethane, (4) diluting graphene with isopropyl alcohol, mixing with silane coupling agent, stirring at room temperature for 25-35 minutes to obtain silane coupling agent-modified graphene, (5) adding prepolymer of aqueous polyurethane into silane coupling agent modified graphene, adding deionized water and small molecular amine chain extender, performing high-speed shear emulsification dispersion at room temperature for 15-30 minutes, and removing solvent by distillation under reduced pressure.