▎ 摘　　要

NOVELTY - Biomimetic nanocomposite material with enhanced conductivity and mechanical properties by supramolecular action, is claimed. The material has a shell-like layered and ordered brick-wall structure on the micro-nano scale. The inorganic phase of two-dimensional nanosheet MXene or graphene oxide. The organic polymer phase is waterborne polyurethane (WPU) with different (2-ureido-4(1H) pyrimidinone) (UPy) groups in its side groups, and the molecular structure contains urethane groups that can form a heavy hydrogen bond, forming two urea groups with heavy hydrogen bonds and UPy groups capable of forming quadruple hydrogen bonds. The UPy content is 15%, and the distance between the nanosheets determined by the X-ray diffraction test is the layers have weak singlet hydrogen bonds and strong double and quadruple hydrogen bonds. USE - The biomimetic nanocomposite material is useful in field of electromagnetic shielding and electric heating. ADVANTAGE - The method enhances conductivity and mechanical properties of material by changing polyurethane containing different four-fold hydrogen bond unit without increasing the conductive filler, and obtains material with good flexibility and good conductivity, and high strength. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for: a method for preparing the biomimetic nanocomposite material, comprising (i) drying the macromolecular diol in a vacuum oven at 90-110 degrees C for 2-24 hours, adding into a drying reactor with a mechanical stirring device, and adding diisocyanate dropwise, where the molar ratio of the diisocyanate and the macromolecular diol is 1.2:1-3:1, and heating to 75-85 degrees C for 2-4 hours, dissolving the hydrophilic chain extender and UPy chain extender into the strongly polar aprotic solvent after removing water, and adding the chain extender solution into the reaction system, reacting at 75-85 degrees C for 2-4 hours, where amount of UPy chain extender is 1-30 mol.% of the hydrophilic chain extender, and the total amount is 0.8-1.2 times the molar mass of isocyanate groups theoretically remaining after the reaction, cooling the system to less than 50 degrees C, adding neutralizer, and reacting for 10-30 minutes, where the amount of neutralizer is 0.9-1.1 times the molar mass of the hydrophilic chain extender used, adjusting the stirring speed to 2000-5000 revolutions/minute, adding deionized water to emulsify and disperse for 15-45 minutes to obtain WPU-UPy-x emulsion; (ii) diluting WPU-UPy-x with water into 0.1-20% emulsion, preparing two-dimensional nanosheets are into 0.01-5% aqueous dispersion, adding two-dimensional nanosheet dispersion into the WPU-UPy-x emulsion, and continuously stirring for 2-8 hours to make WPU-UPy-x fully adsorb on the two-dimensional nanosheets to prepare WPU-UPy-x and two-dimensional nanosheets A composite dispersion with a mass ratio of 7:3-0.5:9.5, preparing nanocomposite film with a thickness of 2 mu m-2mm using the composite dispersion by vacuum filtration, solvent volatilization or coating and drying the nanocomposite film, and immersing in hydrogen iodide at 60 degrees C for 8 hours, and washing and drying to obtain WPU-UPy-x/two-dimensional nanosheet composite material.