Preparation method and application of graphene modified polyurethane film-forming agent

[0024] The preparation of the graphene oxide used in the present invention:

[0025] (1) Low-temperature reaction, add 30mL of concentrated sulfuric acid to a dry beaker one by one, place in a low-temperature reaction bath, wait until the temperature of concentrated sulfuric acid is around 0°C, add 10g of graphite under strong stirring, and add potassium permanganate several times 30g, control the temperature of the reaction solution at 10-15°C and stir for two hours;

[0026] (2) Medium-temperature reaction, place the beaker in step (1) in a 35°C constant temperature water bath, and continue stirring for half an hour when the temperature of the reaction solution rises to 35°C;

[0027] (3) For high-temperature reaction, add deionized water under stirring, control the reaction temperature within 100°C, continue stirring for half an hour, dilute the reaction solution by 800~1000mL with deionized water, add 5% hydrogen peroxide, and filter while it is hot. Wash with 5% hydrochlo...

[0038] A preparation method of graphene modified polyurethane film-forming agent has the following steps:

[0039] (1) Under the protection of nitrogen, disperse graphene into a benign organic solvent tetrahydrofuran, stir and disperse evenly, add 2,4-toluene diisocyanate in an amount of 0.1% by mass, and react at 20-30°C for 0.1 hour , to obtain a functionalized graphene dispersion;

[0040] (2) According to the molar ratio of polyethylene glycol 200 and 2,4-toluene diisocyanate added in the previous step of 1.1:2, add polyethylene glycol 200 to the functionalized graphene dispersion obtained in the previous step, Control the reaction temperature at 25-40°C, add a benign organic solvent tetrahydrofuran to dilute when the viscosity of the system increases, and measure the residual isocyanate NCO group through real-time sampling of the mixture in the reaction system. When the mass fraction of the NCO group decreases to the initial value Half of the time, the graphene-modified ...

[0045] A preparation method of graphene modified polyurethane film-forming agent has the following steps:

[0046] (1) Under the protection of nitrogen gas, disperse graphene oxide into a benign organic solvent N,N-dimethylacetamide, stir and disperse evenly, add diphenylmethane diisocyanate in an amount of 50% by mass, and After reacting at 90-100°C for 20 hours, a functionalized graphene dispersion is obtained;

[0047] (2) According to the molar ratio of polytetrahydrofuran polyether 2000 diol and diphenylmethane diisocyanate added in the previous step of 1.9:2, add polytetrahydrofuran polyether diol 2000 to the functionalized graphite obtained in the previous step In the olefin dispersion, control the reaction temperature at 140-150°C, add a benign organic solvent N,N-dimethylacetamide to dilute when the viscosity of the system increases, and carry out real-time sampling of the mixture in the reaction system to check the residual isocyanate NCO group Determination, when t...