▎ 摘　　要

NOVELTY - Aqueous polyurethane composite material comprises diisocyanate, hydrophilic chain extender, organic tin catalyst, small molecular chain extender, neutralizing agent, modified graphene oxide powder, deionized water, internal cross-linking agent and hydroxy terminated dihydric alcohol in a mass ratio of (3-6): (0.5-1.5): (0.015-0.04): (1.0-3.0): (0.5-1.25): (1.7-5): (200-350): (0.1-0.3): 1. USE - Used as aqueous polyurethane composite material. ADVANTAGE - The composite material: has excellent stability and high heat-conducting performance; and can realize the water absorption rate of 20-40%, the ethanol swelling rate of 10-35%, the tensile strength of 10-25 microPa, the elongation at break is 500-800% and thermal conductivity of 0.3-0.7W/(m.K). DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing the aqueous polyurethane composite material comprising (i) taking the above raw materials, (ii) magnetically stirring graphene oxide, triethylamine and 3-aminopropyltriethoxysilane in an ethanol-aqueous solution at normal temperature for 24 hours, filtering the obtained reaction mixed solution using filtering device, washing the reaction mixed solution with absolute ethanol and a deionized water agent for three times until the reaction mixed solution is neutral to obtain G1, ultrasonically dispersing the reaction mixed solution for 60 minutes, dropwise adding triethanolamine to reduce the reaction mixed solution, magnetically stirring the reaction mixed solution for 24 hours at normal temperature, washing the reaction mixed solution for 3 times to be neutral by using absolute ethanol and deionized water respectively, and finally drying the reaction mixed solution for 2 hours in a drying oven at 60degrees Celsius to obtain modified reduced graphene oxide powder G2, (iii) stirring and mixing hydroxy-terminated diol, diisocyanate, an internal crosslinking agent and an organic tin catalyst in a small amount of acetone, uniformly dissolving, stirring and reacting at 80-85degrees Celsius, stirring and reacting at the rotating speed of 400-600 rotation/minute (rpm) for 3-4 hours and stopping the reaction when the reaction end point is reached to obtain an isocyanate group-terminated prepolymer A, (iv) adding a hydrophilic chain extender into the prepolymer A in proportion, reacting at 70-75degrees Celsius, stirring at a rotating speed of 400-600 rpm for 2-3 hours and stopping the reaction when a reaction end point is reached to obtain an isocyanate group-terminated ionized polymer B, (v) adding a small-molecule chain extender into the ionized polymer B blocked by the isocyanate group in proportion, heating to 75-85degrees Celsius, continuing to react, stirring and reacting for 2-3 hours at the rotating speed of 400-600 rpm and stopping the reaction when the reaction end point is reached to obtain an ionized polymer C blocked by the isocyanate group, (vi) cooling the ionized polymer C obtained in the resultant step to 55-65degrees Celsius, adding an acetone dispersion liquid of G2 which is ultrasonically dispersed in advance and stirring and reacting for 2-3 hours at the rotating speed of 400-600 rpm and then cooling to 30-40degrees Celsius, adding a neutralizing agent to neutralize carboxylic acid groups in the obtained ionized polymer C, stirring at the rotation speed of 400-600 rpm for 20-40 minutes for reaction, adding deionized water at the high rotation speed of 1200-1400 rpm, stirring for 20-40 minutes to form a cross-linked composite aqueous polyurethane emulsion, distilling to recover acetone to obtain composite aqueous polyurethane emulsion and pouring into a circular tetra chloroethylene mold with the diameter of 4cm, drying at room temperature for 48 hours and drying in a vacuum drying oven for 24 hours to obtain the final product.