▎ 摘　　要

NOVELTY - Bio-based nano-composite epoxy coating comprises a hard inorganic phase and a soft organic phase of a self-repairing type bio-based epoxy polymer system. The inorganic phase includes reversible quadruple hydrogen bond 2-ureido-41H-pyrimidinone-isocyanate (UPy-NCO) molecularly modified graphene oxide (GO-UPy), hydrotalcite, boron nitride, and/or hydroxyapatite two-dimensional nanomaterials. The organic phase includes three components of bio-based epoxy resin, curing agent and branched IPDA (UPy-IPDA-NH2) with 2-ureido-41H-pyrimidinone (UPy). The bio-based epoxy resin is bio-based cardanol epoxy resin (NC-514), phosphorus-containing itaconic acid-based epoxy resin (EADI), eugenol-based epoxy resin and/or any other bio-based epoxy resin. The curing agent is isophorone diamine (IPDA), polyetheramine and/or polyamide curing agent. USE - The nano-compositeepoxy coating is useful for surface protection of materials i.e. surface corrosion protection of metal materials (all claimed). Can also be used in electronic device, engineering device and metal surface as protection technology field. ADVANTAGE - The nano-composite epoxy coating has good mechanical performance, fast and self-repairing capability and good corrosion resistance. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: a method for preparing bio-based nanocomposite epoxy coating comprising (1) adding 2-Amino-4-hydroxy-6-methylpyrimidine and hexamethylene diisocyanate (HDI) to a round bottom flask, reacting at high temperature under nitrogen atmosphere for 12 hours, cooling to room temperature, use n-hexane to wash off the unreacted HDI, drying the product in a vacuum drying oven overnight to obtain a white powder (UPy-NCO), taking graphene oxide (GO) and UPy-NCO to be dispersed in N,N-dimethylformamide solution, and adding dibutyltin dilaurate, heating to 30-50°C under nitrogen atmosphere, after 24 hours of reaction, collecting the mixture by vacuum filtration, and finally washing the product with N,N-dimethylformamideand ethanol to obtain GOUPy, (2) dispersing 2-Amino-4-hydroxy-6-methylpyrimidine and N,N carbonyldiimidazole (CDI) in dimethyl sulfoxide, stirring at 70-90℃ for 1-3 hours, purifying the solid product by filtration, washing 2-4 times with cold acetone, and drying in vacuo to obtain a white powder (UPy-CDI), dissolving UPy-CDI in IPDA, stirring at 40-50°C for 48 hours, adding resulting mixture to n-hexane at 0°C, stirring uniformly, dissolving the lower layer solution in the above mixture in dichloromethane (DCM), washing with brine and deionized water 2-4 times each, drying the mixture over anhydrous sodium sulfate, removing DCM by rotary evaporation, and drying in vacuo overnight to give UPy-IPDA-NH2, and completely mixing and stirring well the NC-514, IPDA and UPy-IPDA-NH2 and the solvent until the mixture is completely dissolved to obtain a yellow mixture, (3) placing the GO-UPy obtained in step (1) in a solvent, and ultrasonically dispersing to obtain a black graphene oxide dispersion solution, (4) placing the yellow mixture in a high-speed stirring disperser and continuously stirred at a rotating speed of 1000-3000 revolutions/minute, dropwisely adding the black graphene oxide dispersion solution to the yellow mixture, stirring and dispersing for 12 hours to fully mixing to obtain a black mixture suspension, which is a nacre-inspired bio-based nanocomposite epoxy coating; and a use method of bio-based nanocomposite epoxy coating comprising using wire rod coater, automatic film coater, spraying or spin coating to coat the Q235 carbon steel substrate after sanding and pretreatment, curing the coated carbon steel substrate at 50-70℃ for 24 hours, and then curing at 70-90℃ for 24 hours to obtain a nacre-type nanocomposite epoxy coating with self-repairing function.