Supramolecularly woven crosslinked polyurethane prepolymers and compositions and methods of making the same

Abstract

The application relates to the technical field of polyurethane synthesis, and discloses a kind of polyurethane prepolymer and composition based on supermolecular weaving crosslinking and a preparation method thereof, wherein the crosslinking agent in the polyurethane prepolymer includes a compound shown in formula I and an organic copper salt; the molar ratio of the compound shown in formula I and the organic copper salt is 1:1.8-3; the organic copper salt is selected from tetraethyl cyanide copper tetrafluoroborate and / or tetraethyl cyanide copper hexafluorophosphate. The application utilizes the dynamic nature of mechanical interlocking supermolecular structure to realize the polymerization of weaving topological structure through ectopic ring-opening polymerization strategy. The weaving polymer can be used as a crosslinking agent of polyurethane composition, which can simultaneously endow the polyurethane composition with higher mechanical properties and good tensile properties, greatly improving the tensile toughness of polyurethane.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polyurethane synthesis, in particular to a kind of polyurethane prepolymer and composition based on supermolecular weaving crosslinking and preparation method thereof. BACKGROUND

[0002] Polyurethane composition as material adhesive has the advantages of adjustable softness and hardness, low temperature resistance, good flexibility, large bonding strength, etc., can bond metal, non-metal and other materials, and has broad application prospect in the fields of building, electronic materials and decoration. In order to adjust the mechanical properties of polyurethane, the existing technology often adjusts the structure of polyurethane composition by adding multifunctional crosslinking agent or changing the ratio of soft and hard segments, and adjusts the mechanical properties by adding auxiliary agent and filler to adapt to the application requirements.

[0003] However, the traditional polyurethane composition with high hard segment content has high mechanical strength but poor tensile performance, and when the polyurethane composition is damaged, it shows brittle fracture with low elongation at break. On the contrary, the polyurethane composition with high soft segment content is an elastomer with excellent tensile performance, but its tensile strength is low. The method of adjusting the micro network molecular structure and phase separation state by soft and hard segments cannot simultaneously consider high mechanical properties and excellent tensile performance.

[0004] In order to obtain polyurethane with high mechanical strength and tensile toughness, the application CN111909337A discloses a mechanically interlocked crosslinking agent, which is formed by a long chain axle molecule and at least one ring molecule surrounding the axle molecule to form a rotaxane. This mechanically interlocked rotaxane structure is used in polyurethane composition to simultaneously consider high mechanical properties and excellent tensile performance of polyurethane adhesive.

[0005] CN101633629A synthesizes polyurethane prepolymer with terminal double bond by allyl alcohol ether and isocyanate, and then performs free radical solution polymerization with olefin monomer under the action of initiator to construct a new type of polyurethane crosslinking agent. By adjusting the proportion of components, adhesive with different strength and flexibility can be obtained.

[0006] The inventors found in early research that 4,4'-(1,10-phenanthroline-2,9-diyl) biphenol has dynamic properties and woven crosslinking effects, which can be applied to polyurethane as a crosslinking agent to make the polymer have good self-repairing and processing properties. (Robust and Dynamic Polymer Networks Enabled by Woven Crosslinks, G Li, J Zhao, Z Zhang, X Zhao, L Cheng, Y Liu, Z Guo, W Yu, X Yan Angewandte Chemie, 2022) But the effect of improving the toughness of polyurethane is still insufficient, how to give the polyurethane composition good mechanical strength and at the same time have higher and more excellent toughness is further studied. SUMMARY

[0007] The present application aims at the problem that the mechanical strength and toughness of polyurethane composition cannot be considered, and provides a crosslinking agent with a woven structure, which can significantly improve the elongation at break of the material when used for preparing polyurethane polymer, and greatly improve the toughness under the premise of ensuring the mechanical strength, thereby breaking through some limitations of polyurethane composition in application.

[0008] To achieve the above object, the technical scheme adopted by the present application is:

[0009] A polyurethane prepolymer based on supermolecular woven crosslinking, wherein the crosslinking agent in the polyurethane prepolymer comprises a compound represented by formula I and an organic copper salt; the molar ratio of the compound represented by formula I and the organic copper salt is 1:1.8-3.

[0010]

[0011] The organic copper salt is selected from tetraethyl cyanide copper tetrafluoroborate and / or tetraethyl cyanide copper hexafluorophosphate.

[0012] It is accidentally found in the research of the present application that the compound represented by formula I also has the structure of diphenyl and o-phenanthroline, which can coordinate with the organic metal component to form a supermolecular woven structure, so as to greatly improve the toughness of the polyurethane composition when used as a crosslinking agent for polyurethane, and the elongation at break is greatly improved, which is much better than 4,4'-(1,10-phenanthroline-2,9-diyl) biphenol with similar structure.

[0013] When the organic metal salt is tetraethyl cyanide copper tetrafluoroborate, the coordination structure formed by the compound represented by formula I and tetraethyl cyanide copper tetrafluoroborate is as follows: Such structure is used as a supermolecular crosslinking node in the polyurethane polymerization process.

[0014]

[0015] The method for preparing the compound as shown in formula I comprises the steps of:

[0016] Step 1: preparing the intermediate product as shown in formula II by refluxing 4,7-dihalo-1,10-phenanthroline with 4-[(tetrahydropyran-2-yl)oxy]benzeneboronic acid in the presence of a catalyst;

[0017]

[0018] Step 2: reacting the intermediate product as shown in formula II with methanol in a solution to obtain the compound as shown in formula I.

[0019] The reaction formula is as follows:

[0020]

[0021] The structural formula of the 4,7-dihalo-1,10-phenanthroline is as shown in formula III:

[0022]

[0023] wherein X is selected from F, Cl, Br or I;

[0024] The molar ratio of 4,7-dihalo-1,10-phenanthroline to 4-[(tetrahydropyran-2-yl)oxy]benzeneboronic acid in step 1 is 1:1.8-4;

[0025] The catalyst in step 1 is tricyclohexylphosphine, tris(dibenzylideneacetone)dipalladium and potassium phosphate, and the molar ratio of the three is 1:0.2-0.7:20-35, and the molar ratio of the total amount of the catalyst to 4,7-dihalo-1,10-phenanthroline is 1:4-6;

[0026] The reaction temperature in step 1 is 70-120℃, and the reaction time is 15-30h; the reaction solvent is selected from any one of 1,4-dioxane, toluene, N,N-dimethylformamide, dimethyl sulfoxide and a combined solvent of water;

[0027] The weight ratio of the intermediate product as shown in formula II to methanol in step 2 is 1:0.5-3;

[0028] Preferably, step 2 further comprises an acidifying agent, and the acidifying agent is a combined solvent of hydrogen chloride and 1,4-dioxane in a molar ratio of 1:0.1-10;

[0029] Preferably, the polyurethane prepolymer comprises raw material components: polyether diol, zinc ethylhexanoate, triethanolamine, isophorone isocyanate, the compound as shown in formula I, organic copper salt, polymethylene polyisocyanate, butanone oxime and solvent;

[0030] The solvent comprises any one or more of common solvents such as ethyl acetate and N,N-dimethylformamide.

[0031] Further preferably, the polyurethane prepolymer comprises the following components by weight: polyether diol 20-40 parts, zinc ethyl hexanoate 0.0005-0.006 parts, triethanolamine 0.0005-0.006 parts, isophorone isocyanate 3-15 parts, the compound as shown in formula I 0.3-1.3 parts, copper acetonitrile 0.3-1.3 parts, poly-methylene polyisocyanate 1-5 parts, butanone oxime 1-5 parts, and solvent 5-18 parts.

[0032] Preferably, the poly-methylene polyisocyanate is selected from Wanhua Chemical PM200.

[0033] The application also provides a preparation method of the polyurethane prepolymer based on supermolecular weaving cross-linking, comprising the following steps:

[0034] Step 1: reacting raw materials comprising polyether diol, zinc ethyl hexanoate, triethanolamine, isophorone isocyanate, and solvent at 60-90°C for 0.5-3 hours;

[0035] Step 2: adding the compound as shown in formula I, organic copper salt, and solvent to the reaction solution of step 1 and reacting at 60-90°C for 0.5-3 hours;

[0036] Step 3: adding poly-methylene polyisocyanate and solvent to the reaction solution of step 2 and reacting at 60-90°C for 0.5-3 hours;

[0037] Step 4: measuring the isocyanate content in the reaction solution, adding butanone oxime and solvent and reacting at 60-90°C for 0.5-3 hours to obtain the polyurethane prepolymer.

[0038] The application also provides a polyurethane composition comprising the polyurethane prepolymer.

[0039] Preferably, the polyurethane composition is a delayed curing polyurethane, comprising the following components by weight: polyurethane prepolymer 60-80 parts, epoxy resin 3-10 parts, and polyether amine 10-25 parts.

[0040] Or comprising the following components by weight: polyurethane prepolymer 25-40 parts, epoxy resin 5-25 parts, liquid rubber with core-shell structure 5-15 parts, acrylonitrile-butadiene rubber toughener 10-20 parts, water absorption agent 1-5 parts, filler 15-30 parts, curing agent 1-5 parts, and curing accelerator 0.1-1 part.

[0041] Compared with the prior art, the application has the following beneficial effects:

[0042] (1) Compared with traditional covalent structure crosslinking agent, such as 1,3-butanediol, 1,4-butanediol, trimethylolpropane, glycerol, the present application utilizes the dynamicity of mechanically interlocked supramolecular structure to realize the weaving topology polymer through the ex situ ring-opening polymerization strategy. The weaving polymer can be used as the crosslinking agent of polyurethane composition, which can simultaneously endow the polyurethane composition with higher mechanical property and good tensile property.

[0043] (2) Compared with 4,4'-(1,10-phenanthroline-2,9-diyl)diphenol with N ortho-phenyl substitution structure, 4,4'-(1,10-phenanthroline-4,7-diyl)diphenol with N para-phenyl substitution structure in the present application has significant difference, which can greatly improve the tensile toughness of polyurethane. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 NMR spectrum of 4,4'-(1,10-phenanthroline-4,7-diyl)diphenol prepared for Example 1.

[0045] Figure 2 NMR spectrum of 4,4'-(1,10-phenanthroline-2,9-diyl)diphenol prepared for Comparative Example 1. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with examples. It should be understood that the specific examples described herein are only used to explain the present application, and are not used to limit the present application. Those skilled in the art can modify or replace equivalently on the basis of understanding the technical scheme of the present application, without departing from the spirit and scope of the technical scheme of the present application, which should be covered in the protection scope of the present application.

[0047] The raw materials used in the following specific embodiments are purchased from market reagent companies or chemical distributors.

[0048] Example 1

[0049] The synthesis of weaving structured compound I includes the following steps:

[0050] Step 1: Add 0.45 g of 4,7-dichloro-1,10-phenanthroline, 0.82 g of 4-[(tetrahydropyran-2-yl)oxy]phenylboronic acid, 0.07 g of tricyclohexylphosphine, 0.1 g of tris(dibenzylacetone)dipalladium(O), and 1.58 g of potassium phosphate to a three-necked flask, thoroughly remove oxygen from the flask, then fill with nitrogen. Add 10 mL of deoxygenated 1,4-dioxane and 5 mL of water to the three-necked flask, and then heat to reflux at 95 °C with stirring for 20 hours. Cool the reaction solution to room temperature, wash the reaction solution twice with saturated sodium chloride solution, dry the organic phase with anhydrous magnesium sulfate, and then rotary evaporate to obtain the crude product. Recrystallize the crude product with a mixed solution of dichloromethane and petroleum ether to obtain the intermediate product of formula II.

[0051] Step 2: Dissolve 0.7 g of the aforementioned intermediate of Formula II in 40 mL of methanol, add 1.3 mL of a dry mixed solution of hydrogen chloride / 1,4-dioxane (where the molar concentration of hydrogen chloride is 4 mol / mL), and stir the mixture at room temperature for 6 hours. Filter the reaction solution, wash with 15 mL of chloroform, and add 0.4 g of potassium carbonate, 2.5 mL of chloroform, and 0.25 mL of methanol to the resulting solid. Then, evaporate the mixture to dryness and separate it by column chromatography (methanol / chloroform) to obtain the compound shown in Formula I (hereinafter referred to as crosslinking agent A).

[0052] The reaction equation is as follows:

[0053]

[0054] like Figure 1 As shown, the 600MHz 1H NMR spectrum of the compound represented by product formula I has the following values: δ (ppm): 9.89 (s, 2H), 9.10 (s, 2H), 7.94 (s, 2H), 7.67 (s, 2H), 7.43 (d, J = 8.5 Hz, 4H), 6.99 (d, J = 6.4 Hz, 4H). The test conditions were room temperature, and the test solvent was deuterated dimethyl sulfoxide.

[0055] Comparative Example 1

[0056] The synthesis process of 4,4'-(1,10-phenanthroline-2,9-diyl)bisphenol:

[0057] Step 1: Add 500 mg of 2,9-dichloro-1,10-phenanthroline, 1114 mg of 4-[(tetrahydropyran-2-yl)oxy]phenylboronic acid, 700 mg of tetra(triphenylphosphine)palladium(O), and 15000 mg of sodium carbonate to a three-necked flask, thoroughly remove oxygen from the flask, then fill with nitrogen. Add 180 mL of oxygen-free toluene and 80 mL of oxygen-free water to the three-necked flask, and then heat to reflux at 80 °C with stirring for 20 hours. Then cool the reaction solution to room temperature, wash the reaction solution twice with saturated sodium chloride solution, dry the organic phase with anhydrous magnesium sulfate, and then rotary evaporate to obtain the crude product. The crude product is purified by recrystallization with a mixed solution of dichloromethane and petroleum ether to obtain the intermediate product.

[0058] Step 2: Dissolve 1.4 g of the aforementioned intermediate product in 80 mL of methanol, add 2.6 mL of dry 1,4-dioxane hydrochloride solution (4 mol / mL), and stir the mixture at room temperature for 6 hours. Filter the reaction solution, wash with 30 mL of chloroform, and add 0.7 g of potassium carbonate, 5 mL of chloroform, and 0.5 mL of methanol to the resulting solid. Then, evaporate the mixture to dryness and separate by column chromatography (methanol / chloroform) to obtain 4,4'-(1,10-phenanthroline-2,9-diyl)bisphenol (hereinafter referred to as crosslinking agent B).

[0059] The reaction formula is as follows:

[0060]

[0061] The 600MHz 1H NMR spectrum of the prepared 4,4'-(1,10-phenanthroline-2,9-diyl)bisphenol is as follows: Figure 2 As shown, the specific values ​​are δ (ppm): 9.89 (s, 2H), 8.47 (d, J = 8.4 Hz, 2H), 8.37 (d, J = 8.4 Hz, 4H), 8.27 (d, J = 8.4 Hz, 2H), 7.91 (s, 2H), 7.00 (d, J = 8.5 Hz, 4H). The test conditions were room temperature, and the test solvent was deuterated dimethyl sulfoxide.

[0062] Example 2

[0063] The crosslinking agent A prepared in Example 1 was used to prepare a polyurethane prepolymer, including the following process:

[0064] Step 1: Add 300g of polyether diol (DL-3000D) with a molecular weight of 3000D to a 500ml glass reactor, heat to 108℃, dehydrate under vacuum, keep warm for 1 hour, then cool to 35℃ and seal for later use.

[0065] Step two: 8 grams of dehydrated polyether diol (DL-3000D), 0.001 grams of zinc ethylhexanoate, 0.001 grams of triethanolamine and 2 milliliters of ethyl acetate as solvent were put into the reactor, stirred for 10 minutes, 1.36 grams of isophorone polyisocyanate was added to the reactor under stirring, heated to 85°C for reaction, the reaction time was 1.2 hours, and then cooled to room temperature. A mixture of 0.13 grams of crosslinking agent A and 2 grams of DMF (N, N-dimethylformamide) was put into the reactor, 0.03 grams of tetraethylammonium cyanide tetrafluoroborate was put into the reactor under stirring and nitrogen protection, the mixture was stirred at room temperature for 20 minutes, heated to 80°C for reaction, the reaction time was 50 minutes, and then cooled to room temperature.

[0066] Step three: A mixture of 0.55 grams of polymethylene polyisocyanate (Wanhua Chemical Pm 200) and 5 grams of ethyl acetate was put into the reactor, heated to 65°C for reaction under stirring, the reaction time was 50 minutes, and then cooled to room temperature to obtain a polyurethane prepolymer. The mass fraction of -NCO groups in the polyurethane prepolymer was 2.63%.

[0067] Step four: A mixture of 0.61 grams of butanone oxime and 5 grams of ethyl acetate was put into the reactor, heated to 75°C for reaction under stirring, the reaction time was 2 hours, and then cooled to room temperature to remove the solvent to obtain a room temperature stable polyurethane prepolymer A1.

[0068] The viscosity of the polyurethane prepolymer A1 based on the woven structure crosslinking agent A was measured at room temperature (25°C) and was 33670 cps.

[0069] Comparative example 2

[0070] The crosslinking agent B prepared in Comparative Example 1 was used to prepare a polyurethane prepolymer, including the process:

[0071] Step 1: 300 grams of polyether diol (DL-3000D) with a molecular weight of 3000D were added to a 500ml glass reactor, heated to 108°C, vacuum dehydrated, incubated for 1 hour, then cooled to 35°C, and sealed for standby.

[0072] Step 2: Put 8 grams of dehydrated polyether diol (DL-3000D), 0.001 grams of zinc ethylhexanoate, 0.001 grams of triethanolamine and 2 milliliters of ethyl acetate as a solvent into the reactor, stir for 10 minutes, add 1.36 grams of isophorone polyisocyanate to the reactor under stirring, heat to 85°C and keep the temperature for 1.2 hours, and then cool to room temperature. Put 0.13 grams of crosslinking agent B and 2 grams of DMF (N, N-dimethylformamide) into the reactor, and then put 0.03 grams of tetraethylammonium copper tetrafluoroborate into the reactor under stirring and nitrogen protection. Stir the mixture at room temperature for 20 minutes, heat to 80°C and keep the temperature for 50 minutes, and then cool to room temperature.

[0073] Step three: Put 0.55 grams of polymethylene polyisocyanate (Wanhua Pm 200) and 5 grams of ethyl acetate into the reactor, stir, heat to 65°C and keep the temperature for 50 minutes, and then cool to room temperature to obtain a polyurethane prepolymer. The mass fraction of -NCO groups in the polyurethane prepolymer is 2.56%.

[0074] Step four: Put 0.61 grams of butanone oxime and 5 grams of ethyl acetate into the reactor, stir, heat to 75°C and keep the temperature for 2 hours, and then cool to room temperature to remove the solvent to obtain a room temperature stable polyurethane prepolymer B1.

[0075] The viscosity of the polyurethane prepolymer B1 based on the woven structure crosslinking agent B is 37800 cps at room temperature (25°C).

[0076] Comparative Example 3

[0077] The process for preparing a polyurethane prepolymer based on covalently crosslinked pentaerythritol is as follows:

[0078] Step one: Put 300 grams of polyether diol (DL-3000D) with a molecular weight of 3000D into a 500ml glass reactor, heat to 108°C, vacuum dehydrate, keep the temperature for 1 hour, then cool to 35°C, and seal for standby.

[0079] Step two: Put 8 grams of dehydrated polyether diol (DL-3000D), 0.001 grams of zinc ethyl hexanoate, 0.001 grams of triethanolamine and 2 milliliters of ethyl acetate as a solvent into the reactor, stir for 10 minutes, add 1.36 grams of isophorone polyisocyanate to the reactor under stirring, heat to 85°C and keep for reaction, the reaction time is 1.2 hours, cool to room temperature. Put 0.06 grams of pentaerythritol and 2 grams of DMF (N, N-dimethylformamide) into the reactor, stir the mixture at room temperature for 20 minutes under stirring and nitrogen protection, heat to 80°C and keep for reaction, the reaction time is 50 minutes, cool to room temperature.

[0080] Step three: Put 0.55 grams of polymethylene polyisocyanate (Wanhua Chemical Pm 200) and 5 grams of ethyl acetate into the reactor, heat to 65°C and keep for reaction under stirring, the reaction time is 50 minutes, cool to room temperature to obtain a polyurethane prepolymer, and the mass fraction of -NCO groups in the polyurethane prepolymer is 2.60%.

[0081] Step four: Put 0.61 grams of butanone oxime and 5 grams of ethyl acetate into the reactor, heat to 75°C and keep for reaction under stirring, the reaction time is 2 hours, cool to room temperature, and remove the solvent to obtain a room temperature stable polyurethane prepolymer C1.

[0082] The viscosity of the pentaerythritol polyurethane prepolymer C1 is 40300 cps at room temperature (25°C).

[0083] Application example 1

[0084] A polyurethane preparation process, which mainly explores the performance of the polyurethane bulk material:

[0085] According to the mass fraction of raw materials in Table 1, add epoxy resin and polyether amine D900 to the polyurethane prepolymers A1, B1 and C1, mix and stir under the conditions of 30-40°C revolution 15 Hz and rotation 10 Hz, vacuum degassing for 5-15 minutes to obtain delayed curing polyurethanes D1, D2 and D3.

[0086] Application example 2

[0087] A polyurethane composition preparation process, which mainly explores the performance of the adhesive after mixing the polyurethane with the remaining powder materials:

[0088] According to the raw material quality parts in Table 1, the epoxy resin, the liquid rubber with core-shell structure, the nitrile rubber toughening agent, and the diluent were added to the polyurethane prepolymer A1, B1, and C1, and the materials were placed in a dynamic mixer. Mixing and stirring were carried out at 30-40°C, 15Hz revolution, and 30Hz rotation. Vacuum degassing was carried out for 8-25 minutes to obtain an epoxy resin initial mixture. Then, the water absorbing agent, the filler, the heat-activated latent curing agent, and the curing accelerator were added to the epoxy resin initial mixture. Mixing and stirring were carried out at 30-40°C, 15Hz revolution, and 10Hz rotation. Vacuum degassing was carried out for 8-25 minutes to obtain the delayed curing polyurethane compositions D4, D5, and D6.

[0089] In the above application examples 1-2, the epoxy resin used is E51 type liquid epoxy resin; the liquid rubber with core-shell structure is MX154 core-shell rubber particle / epoxy resin (with a core-shell particle mass fraction of 40%); the nitrile rubber toughening agent is CTBN2050 liquid nitrile rubber modified with epoxy resin; the water absorbing agent is 4A molecular sieve; the filler is fumed white carbon black; the curing agent is Dyhard 100S dicyandiamide curing agent; and the curing accelerator is UR700, all of which are purchased on the market.

[0090] The polyurethane and its compositions D1-D6 were tested for performance at room temperature, and the test method referred to the tensile specimen national standard GBT228-2002. Specifically, the test substrate was cleaned with acetone. The aforementioned delayed curing polyurethane composition was uniformly applied to a mold, and then the mold was placed at 160°C for 1 hour. Subsequently, the molded test sample was taken out for testing. The tensile strength and elongation at break were tested three times, and the results are shown in Table 1.

[0091] Table 1 Raw material composition and performance test results of the polyurethane and polyurethane composition of the application examples

[0092]

[0093] As can be seen from the results in Table 1, D1 and D4 are polyurethane compositions prepared using the mechanical interlocking woven structure crosslinking agent A of the application. Compared with the traditional pentaerythritol crosslinking agent of D3 and D6, the elongation at break is greatly improved, the bulk polyurethane is increased by 3 times, and the elongation at break of the polyurethane composition (57.39%) is increased by 462% compared with the covalent structure (10.21%), which is very obvious.

[0094] Compared with the crosslinking agent B of the applicant's early research, although the structures are similar, the effects are quite different due to the different substitution positions of the phenol structure. The elongation at break of the composition obtained by the dynamic coordination crosslinking agent B (20.03%) is only increased by 96.2% compared with the covalent structure (10.21%).

Claims

1. A supramolecular weaving crosslinking based polyurethane prepolymer, characterized in that, The crosslinking agent in the polyurethane prepolymer comprises a compound shown in formula I and an organic copper salt; the molar ratio of the compound shown in formula I and the organic copper salt is 1:1.8-3; The organic copper salt is selected from tetraethyl cyanide copper tetrafluoroborate and / or tetraethyl cyanide copper hexafluorophosphate.

2. The supramolecular weaving crosslinking based polyurethane prepolymer according to claim 1, wherein, The preparation method of the compound shown in formula I comprises the following steps: Step 1, preparing an intermediate product shown in formula II by refluxing 4,7-dihalo-1,10-phenanthroline and 4-[(tetrahydropyran-2-yl)oxy]benzeneboronic acid under the action of a catalyst; Step 2, reacting the intermediate product shown in formula II with methanol in a solution to obtain the compound shown in formula I.

3. The supramolecular weaving crosslinking based polyurethane prepolymer according to claim 2, wherein, The structure of the 4,7-dihalo-1,10-phenanthroline is shown in formula III: wherein X is selected from F, Cl, Br or I.

4. The supramolecular weaving crosslinking based polyurethane prepolymer according to claim 2, wherein, The molar ratio of 4,7-dihalo-1,10-phenanthroline and 4-[(tetrahydropyran-2-yl)oxy]benzeneboronic acid in step 1 is 1:1.8-4; And / or, the catalyst in step 1 is tricyclohexylphosphine, tris(dibenzylideneacetone)dipalladium and potassium phosphate, and the molar ratio of the three is 1:0.2-0.7:20-35; the total catalyst usage and the molar ratio of 4,7-dihalo-1,10-phenanthroline are 1:4-6; And / or, the reaction temperature in step 1 is 70-120℃, the reaction time is 15-30h; the reaction solvent is selected from any one of 1,4-dioxane, toluene, N,N-dimethylformamide, dimethyl sulfoxide and a combined solvent of water.

5. The supramolecular weaving crosslinking based polyurethane prepolymer as claimed in claim 2, wherein, The weight ratio of the intermediate product shown in formula II and methanol in step 2 is 1:0.5-3; And / or, step 2 further comprises an acidifying agent, and the acidifying agent is a combined solvent of hydrogen chloride and 1,4-dioxane in a molar ratio of 1:0.1-10.

6. The supramolecular weaving crosslinking based polyurethane prepolymer as claimed in claim 1, wherein, The polyurethane prepolymer comprises the following components in the following weight proportions: polyether diol 20-40 parts, zinc ethylhexanoate 0.0005-0.006 parts, triethanolamine 0.0005-0.006 parts, isophorone isocyanate 3-15 parts, the compound shown in formula I 0.3-1.3 parts, organic copper salt 0.3-1.3 parts, polymethylene polyisocyanate 1-5 parts, butanone oxime 1-5 parts and solvent 5-18 parts.

7. The method of making supramolecular weaving crosslinking based polyurethane prepolymer as claimed in claim 6, wherein, The method comprises the following steps: Step 1, reacting raw materials comprising polyether diol, zinc ethylhexanoate, triethanolamine, isophorone isocyanate and solvent at 60-90℃ for 0.5-3 hours; Step 2, adding the compound shown in formula I, acetonitrile copper and solvent to the reaction solution of step 1 and reacting at 60-90℃ for 0.5-3 hours; Step 3, adding polymethylene polyisocyanate and solvent to the reaction solution of step 2 and reacting at 60-90℃ for 0.5-3 hours; Step 4, measuring the isocyanate content in the reaction solution, adding butanone oxime and solvent and reacting at 60-90℃ for 0.5-3 hours to obtain the polyurethane prepolymer.

8. A polyurethane composition, characterized by, The polyurethane prepolymer comprises the following components in the following weight proportions: polyether diol 20-40 parts, zinc ethylhexanoate 0.0005-0.006 parts, triethanolamine 0.0005-0.006 parts, isophorone isocyanate 3-15 parts, the compound shown in formula I 0.3-1.3 parts, organic copper salt 0.3-1.3 parts, polymethylene polyisocyanate 1-5 parts, butanone oxime 1-5 parts and solvent 5-18 parts.

9. The polyurethane composition according to claim 8, characterized in that, The polyurethane prepolymer comprises the following components in the following weight proportions: polyether diol 20-40 parts, zinc ethylhexanoate 0.0005-0.006 parts, triethanolamine 0.0005-0.006 parts, isophorone isocyanate 3-15 parts, the compound shown in formula I 0.3-1.3 parts, organic copper salt 0.3-1.3 parts, polymethylene polyisocyanate 1-5 parts, butanone oxime 1-5 parts and solvent 5-18 parts.

10. The polyurethane composition according to claim 8, characterized in that, The polyurethane composition comprises the following components by weight: 25-40 parts of the polyurethane prepolymer according to any one of claims 1-7, 5-25 parts of an epoxy resin, 5-15 parts of a liquid rubber with core-shell structure, 10-20 parts of a nitrile rubber toughener, 1-5 parts of a water absorbent, 15-30 parts of a filler, 1-5 parts of a curing agent, and 0.1-1 parts of a curing accelerator.

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