▎ 摘　　要

NOVELTY - An aqueous polyurethane coating comprises 30-50 pts. wt. aqueous polyurethane emulsion, 3-10 pts. wt. graphene, 10-20 pts. wt. rare earth oxide, 10-20 pts. wt. boron carbide, 5-10 pts. wt. nano-aluminum oxide emulsion, 1-2 pts. wt. aqueous dispersant, 1-2 pts. wt. aqueous defoamer, 1-2 pts. wt. aqueous wetting agent, 1-2 pts. wt. aqueous leveling agent, 0.5-2 pts. wt. aqueous suspending agent and 2-3 pts. wt. aqueous thickener. USE - Aqueous polyurethane coating (claimed). ADVANTAGE - The aqueous polyurethane coating has excellent neutron radiation resistance and mechanical properties. DETAILED DESCRIPTION - An aqueous polyurethane coating comprises 30-50 pts. wt. aqueous polyurethane emulsion, 3-10 pts. wt. graphene, 10-20 pts. wt. rare earth oxide, 10-20 pts. wt. boron carbide, 5-10 pts. wt. nano-aluminum oxide emulsion, 1-2 pts. wt. aqueous dispersant, 1-2 pts. wt. aqueous defoamer, 1-2 pts. wt. aqueous wetting agent, 1-2 pts. wt. aqueous leveling agent, 0.5-2 pts. wt. aqueous suspending agent and 2-3 pts. wt. aqueous thickener. The preparation method of aqueous polyurethane emulsion involves: (1) reacting 60-90 g macromolecular dihydric alcohol, 30-120 g diisocyanate and 5-25 g organic fluorine modified graphene monomer at 90-100 degrees C for 2-4 hours; (2) adding 20-50 g small molecular chain extender, 8-20 g hydrophilic chain extender (I), 20-50 g solvent and 0.1-0.5 g catalyst at 60-80 degrees C for 3-6 hours; (3) adding 20-50 g solvent and 5-15 g hydrophilic chain extender (II) at 50-60 degrees C for 0.5-1 hours; and (4) adding 50-100 g solvent and 6-15 g salt-forming agent under high speed shearing, stirring for 1-5 minutes, then adding 300-800 g water to carry out high-speed dispersion and emulsification, adding 10-30 g chain extender diluted by 2-5 times of water, carrying out high-speed dispersion for 30-60 minutes, and removing solvent under vacuum to obtain product. An INDEPENDENT CLAIM is included for preparation of aqueous polyurethane coating, which involves: (1) adding aqueous dispersant, aqueous defoamer, and aqueous suspending agent to aqueous polyurethane emulsion, and evenly dispersing; (2) adding graphene, rare earth oxide, boron carbide and nano-aluminum oxide emulsion, and carrying out ball milling and dispersion; and (3) adding aqueous wetting agent, aqueous leveling agent and aqueous thickening agent, uniformly dispersing the mixture at low-speed, and then degassing under vacuum to obtain product.