▎ 摘　　要

NOVELTY - Coating comprises primer and topcoat, where the primer includes primer prepolymer solution, chain extender and solvent, the monomers of primer prepolymer solution comprise polytetrahydrofuran ether glycol, toluene-2,4-diisocyanate and double-ended fluorine-containing hydroxypropyl polydimethylsiloxane, the theoretical content of NCO in primer prepolymer solution is 7-9%, and the mass ratio of double-end fluorine-containing hydroxypropyl polydimethylsiloxane to polytetrahydrofuran ether glycol is 3-5%, the mass ratio of solvent to primer prepolymer solution is 1:5-2:100, the solvent includes ethyl acetate, butyl acetate, dimethylformamide, toluene, Virahol and/or acetone, the chain extender includes 1,4-butanediol and 3,3'-dichloro-4,4'-diaminodiphenylmethane in molar ratio of 1,4-butanediol and 3,3'-dichloro-4,4'-diaminodiphenylmethane is 1:1, and the topcoat comprises graphene dispersion, topcoat prepolymer solution and/or chain extender. USE - The coating is useful for surface of ship component i.e. pump, ship propeller and turbine blade. ADVANTAGE - The coating: has natural porous structure, which can actively buffer cavitation shock wave and reduce fatigue damage caused by sudden pressure changes; has strong hydrophobicity, which can actively resist water, and prevents from failing due to intrusion of water; and also has improved hardness and tensile strength, improved heat resistance and heat dissipation ability, improved ability to resist cavitation and impact, improved service life. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: preparing bionic porous anti-cavitation coating, comprising (i) (a) measuring materials, (b) pouring polytetrahydrofuran ether glycol and double-ended fluorine-containing hydroxypropyl polydimethylsiloxane into rotary bottle of rotary evaporator, distilling under reduced pressure at 120℃ and 0.093 MPa vacuum for 2 hours, cooling to 60℃, and bottling and sealing for storage, (c) pouring toluene-2,4-diisocyanate solution into four-necked flask, heating oil bath to 50℃ and passing nitrogen gas, then pouring polytetrahydrofuran ether glycol into constant pressure dropping funnel and dropwisely adding to four-necked flask at rate of 1-20 drops/seconds, completing dropwise addition, ensuring temperature of 50℃, continues reacting for 30-60 minutes, monitoring temperature of solution at same time, if the temperature of solution drops to ≤50℃, starting to pour double-ended fluorine-containing hydroxypropyl polydimethylsiloxane into constant pressure dropping funnel and dropwise into four-necked flask at rate of 1-20 drops/seconds, raising temperature of oil bath to ensure temperature of solution to 85℃, performing reaction at constant temperature for 3 hours, cooling to room temperature, sealing and storing in bottle to obtain primer prepolymer solution, (d) mixing 1,4-butanediol with 3,3'-dichloro-4,4'-diaminodiphenylmethane as chain extender, vacuuming in vacuum drying oven and heating to 110℃ to melt 3,3'-dichloro-4,4'-diaminodiphenylmethane to obtain chain extender, (v) mixing primer prepolymer solution with solvent, and fully stirring after mixing to obtain mixed solution, and (vi) mixing primer prepolymer solution with solvent mixed solution and chain extender based on proportion, and rapidly stirring for 15 minutes, and vacuuming and deaerating for 1 minutes after stirring to obtain primer, and (ii) (a) pouring graphene into solvent, continuously ultra-sonicating for 4 hours, dispersing graphene in solvent to obtain graphene dispersion liquid, (b) measuring polytetrahydrofuran ether diol and diphenylmethane-4,4'-diisocyanate, pouring diphenylmethane-4,4'-diisocyanate into four-necked flask, heating oil bath to 50℃ and passing nitrogen gas, then pouring polytetrahydrofuran ether diol into constant pressure dropping funnel and dropwisely adding to four-necked flask at speed of 1-20 drops/seconds, completing dropwise addition, ensuring temperature of 50℃, continues to reacting for 30-60 minutes, simultaneously monitoring temperature of solution, if the temperature of solution drops ≤50℃, increasing temperature of oil bath to ensure temperature of solution to 80℃, carrying out constant temperature reaction for 3 hours, cooling to normal temperature, bottling and sealing for preservation, (c) mixing topcoat prepolymer solution with graphene dispersion, ultrasonically treating for 4 hours, and stirring for 4 hours to obtain mixed solution, and (d) mixing mixed solution with chain extender 1,4-butanediol based on ratio of mass ratio of topcoat prepolymer solution to chain extender of 25-27:1, and rapidly stirring for 15 minutes, vacuuming and defoaming for 1 minutes to obtain topcoat. coating, prepared by above method.