Waterborne polyurethane resin with high heat resistance and preparation method thereof

Abstract

The invention discloses waterborne polyurethane resin with high heat resistance and a preparation method of the waterborne polyurethane resin, and relates to the technical field of waterborne polyurethane resin. Comprising the following components: polycaprolactone glycol, polytetrahydrofuran glycol, isophorone diisocyanate, hydrogenated phenyl methane diisocyanate, 2, 2-dimethylolpropionic acid, 3-methylolpropane, a modified carbon nanotube, an auxiliary agent, hydrazine hydrate, dibutyltin dilaurate and deionized water. According to the invention, by introducing the modified carbon nanotubes, the auxiliary agent and the like and combining a special physical and chemical treatment mode, the mechanical property and heat resistance of the waterborne polyurethane resin are improved, and the quality of the waterborne polyurethane resin is improved, so that the waterborne polyurethane is more widely applied.

Description

Technical Field

[0001] The invention belongs to the technical field of waterborne polyurethane resin preparation, and particularly relates to a waterborne polyurethane resin with high heat resistance and a preparation method thereof. Background Art

[0002] Waterborne polyurethane refers to a low-viscosity polyurethane material in which water is used as a dispersion medium and the gel particles are uniformly dispersed in water in a dispersed phase state. According to the dispersion state and the size of the gel particles, waterborne polyurethane can be divided into three types: aqueous solution (particle size <1nm), dispersion (particle size range 1 to 100nm), and emulsion (particle size >100nm).

[0003] Unlike traditional polyurethane materials that contain a large amount of organic solvents, the continuous phase of waterborne polyurethane is water, which has the advantages of low VOC emissions, safety, non-toxicity, no pollution to the environment, energy saving, and low cost. Waterborne polyurethane can be compounded with a variety of waterborne materials, and the performance can be improved by adjusting the ratio to meet product requirements. It has a high potential application value. Therefore, waterborne polyurethane has received widespread attention from researchers, and its application in leather, coatings, paints, textile finishing, adhesives, sealants and other industries is also developing.

[0004] However, due to the introduction of hydrophilic groups, waterborne polyurethane resins have disadvantages such as poor heat resistance and mechanical properties.

[0005] In order to further improve the application performance of waterborne polyurethane resin, based on this, we propose a waterborne polyurethane resin with high heat resistance and a preparation method thereof, hoping to solve the shortcomings of the prior art. Summary of the invention

[0006] The purpose of the present invention is to provide a waterborne polyurethane resin with high heat resistance and a preparation method thereof in view of the existing problems.

[0007] The present invention is achieved through the following technical solutions:

[0008] A waterborne polyurethane resin with high heat resistance, wherein the raw materials for preparing the waterborne polyurethane resin with high heat resistance include the following components in parts by mass:

[0009] 8.2-9.2 parts of polycaprolactone diol, 23.4-27.4 parts of polytetrahydrofuran diol, 9.8-11.4 parts of isophorone diisocyanate, 17.3-19.3 parts of hydrogenated phenylmethane diisocyanate, 2.6-3.2 parts of 2,2-dihydroxymethylpropionic acid, 2.1-2.7 parts of 3-hydroxymethylpropane, 10.2-11.4 parts of modified nano carbon tubes, 2.4-2.8 parts of auxiliary agent, 3.1-3.5 parts of hydrazine hydrate, 0.007-0.009 parts of dibutyltin dilaurate, and 99-105 parts of deionized water.

[0010] Preferably, the preparation of the modified carbon nanotubes comprises the following steps:

[0011] (1) adding carbon nanotubes and lanthanum acetate in a ratio of 20 to 50:1 into a bead mill, grinding at a speed of 2000 to 3000 rpm for 4 to 8 minutes, then adding into concentrated nitric acid, stirring and mixing under ultrasonic conditions, heating and refluxing for 2 to 3 hours, filtering, washing with deionized water for 3 to 5 times, and drying to obtain a composite material for use;

[0012] (2) Add polyaspartic acid powder and water in a ratio of 1 g:10 mL into a beaker and mix well. Then add the composite material into the solution, stir and disperse evenly, place the dispersion in an oil bath, condense and reflux at 110-120° C. for 10-12 h, and then filter and dry to obtain modified carbon nanotubes.

[0013] Preferably, the volume ratio of the carbon nanotubes to the concentrated nitric acid in step (1) is 3-4:1, and the heating reflux temperature is 110-130°C.

[0014] Preferably, the concentration of the composite material in the dispersion described in step (2) is 4-8 mg / mL.

[0015] Preferably, the preparation method of the auxiliary agent is:

[0016] Sodium alginate and anhydrous ethanol are mixed evenly in a mass ratio of 1:20-30, and 3-aminopropyltrimethoxysilane in an amount of 0.3-0.5 times the mass of sodium alginate is added. After stirring and mixing, ammonia water is added dropwise. After reacting at 90-100° C. for 8-10 hours, tannic acid in an amount of 0.2-0.3 times the mass of sodium alginate is added. After ultrasonic dispersion treatment for 30-40 minutes, the mixture is filtered, dried, and added to BASF EfkaPU 4063 solution, and ultrasonic dispersion treatment is performed for 3-4 hours.

[0017] Preferably, the amount of ammonia water added is 10-20% of the mass of sodium alginate, and the amount of BASF EfkaPU 4063 solution added is 14-18 times the mass of sodium alginate.

[0018] A method for preparing an aqueous polyurethane resin with high heat resistance comprises the following steps:

[0019] S1. Add polycaprolactone diol, polytetrahydrofuran diol and 2,2-dimethylol propionic acid into a reaction kettle in sequence according to the weight of the raw materials, and dehydrate at 100-120° C. for 0.5-1 h;

[0020] S2. Under the protection of nitrogen, add the auxiliary agent, cool to 70-80°C, add isophorone diisocyanate, hydrogenated phenylmethane diisocyanate, and dibutyltin dilaurate while stirring, heat to 90-99°C, stir and react for 2-3 hours, add the modified nano-carbon tubes, and keep the temperature to react until the -NCO content is reduced to 2.5%;

[0021] S3. Cool down to below 50°C, add hydrazine hydrate, stir and disperse at high speed for 1 to 2 minutes, then add deionized water and stir and disperse evenly at high speed, then use 3-hydroxymethylpropane to extend the chain in water, and finally irradiate at a radiation voltage of 110 to 120 kV, a radiation current of 1 mA, and a radiation dose of 60 to 90 KGy to obtain a waterborne polyurethane resin.

[0022] Preferably, the stirring speed of adding while stirring in step S2 is 100-140 rpm.

[0023] Preferably, the stirring speed of the high-speed stirring and dispersing in step S3 is 3000-8000 rpm.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] The present invention provides a waterborne polyurethane resin with high heat resistance and a preparation method thereof. By introducing modified nano carbon tubes, additives and the like and combining special physical and chemical treatment methods, the mechanical properties and heat resistance of the waterborne polyurethane resin are improved, and the quality of the waterborne polyurethane resin is improved, thereby enabling the waterborne polyurethane to be more widely used.

[0026] First, the carbon nanotubes and lanthanum acetate are ground in a certain ratio, and the mechanical force generated by grinding breaks the cohesion of the carbon nanotubes and lanthanum acetate to prevent them from agglomerating. At the same time, the two different substances are ground and mixed, which can prevent the carbon nanotubes from agglomerating again to a large extent and improve the dispersibility of the carbon nanotubes. At the same time, lanthanum acetate is attached to the surface of the carbon nanotubes, which can improve the cross-linking reaction between polymers and between the carbon nanotubes and the matrix components in the subsequent preparation of waterborne polyurethane. Then, a strong oxidant is used to oxidize the auxiliary material, and hydroxyl and carboxyl groups are introduced on the surface of the composite material. The carboxylated composite material and the amino group of polyaspartic acid form an amide bond through an amidation reaction. The polyaspartic acid grafted on the surface of the composite material can effectively improve its dispersion effect in the resin matrix, and can participate in a part of the curing cross-linking reaction, and improve the interface bonding between the carbon nanotubes and the resin matrix. At the same time, due to the large molecular volume of polyethyleneimine, there is a large steric hindrance when grafted on the carbon nanotubes, which greatly reduces the surface energy of the carbon nanotubes and improves its dispersion effect in the resin. Polyaspartic acid molecules have good condensation reactivity and can form a network structure under certain conditions, thereby achieving the curing and reinforcement of the material. In addition, polyaspartic acid can be used as a crosslinker for waterborne polyurethane. Secondly, it can be used as a surfactant for waterborne polyurethane to improve its dispersion performance. The modified carbon nanotubes have a good dispersion state in the resin matrix and form a more stable physical-chemical crosslinked network structure. The modified carbon nanotubes have a stronger interface bonding effect with the matrix, which can give full play to the role of carbon nanotubes and significantly improve their thermal stability and mechanical properties.

[0027] Secondly, the hydroxyl groups on the surface of sodium alginate react with the methoxy groups on 3-aminopropyltrimethoxysilane, and 3-aminopropyltrimethoxysilane is grafted onto the surface of sodium alginate to improve the dispersibility of sodium alginate. Then, tannic acid is added to form chemical bonds with sodium alginate molecules to form a cross-linked network structure. This cross-linking can not only promote emulsification, but also promote the curing cross-linking reaction of waterborne polyurethane resin. The copper matrix has good interface interaction, and then added to BASF Efka PU4063 solution to form a homogeneous additive. In the processing of waterborne polyurethane resin, a cross-linking reaction occurs, further improving the mechanical properties and heat resistance of waterborne polyurethane resin. In addition, the selected raw materials are safe and environmentally friendly, which to a certain extent avoids the harm caused to human body and environment by the existing N-methylpyrrolidone when adjusting the viscosity of waterborne polyurethane.

[0028] Finally, irradiation treatment is carried out, and the double bonds contained in each component undergo free radical polymerization reaction under the action of radiation to form a cross-linked network, which increases the temperature difference of the maximum degradation rate of the soft and hard segments, maximizes the degree of microphase separation, and increases the residual carbon rate, thereby forming a stable whole with excellent heat resistance and good mechanical properties. DETAILED DESCRIPTION

[0029] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Example 1

[0031] A method for preparing an aqueous polyurethane resin with high heat resistance comprises the following steps:

[0032] S1. According to the weight of the raw materials, 8.2 parts of polycaprolactone diol, 23.4 parts of polytetrahydrofuran diol and 2.6 parts of 2,2-dimethylol propionic acid were added to the reactor in sequence, and dehydrated at 100° C. for 0.5 h;

[0033] S2. Under the protection of nitrogen, add 2.4 parts of auxiliary agent, cool to 70°C, add 9.8 parts of isophorone diisocyanate, 17.3 parts of hydrogenated phenylmethane diisocyanate, and 0.007 parts of dibutyltin dilaurate while stirring at 100 rpm, heat to 90°C, stir and react for 2 hours, add 10.2 parts of modified nanocarbon tubes, and keep warm to react until the -NCO content drops to 2.5%;

[0034] S3, cooling to below 50°C, adding 3.1 parts of hydrazine hydrate, stirring and dispersing at 3000 rpm for 1 min, adding 99 parts of deionized water, stirring and dispersing at 3000 rpm, and then chain extending with 2.1 parts of 3-hydroxymethylpropane in water, and finally irradiating at a radiation voltage of 110 kV, a radiation current of 1 mA, and a radiation dose of 60 KGy to obtain a waterborne polyurethane resin.

[0035] The preparation of the modified carbon nanotubes comprises the following steps:

[0036] (1) adding carbon nanotubes and lanthanum acetate in a ratio of 20:1 into a bead mill, grinding at a speed of 2000 rpm for 4 min, then adding into concentrated nitric acid, the volume ratio of carbon nanotubes to concentrated nitric acid being 3:1, stirring and mixing under ultrasonic conditions, heating and refluxing at 110° C. for 2 h, filtering, washing with deionized water 3 times, and drying to obtain a composite material for use;

[0037] (2) Add polyaspartic acid powder and water in a ratio of 1 g:10 mL into a beaker and mix well. Then add the composite material into the solution to make the concentration of the composite material 4 mg / mL. After stirring and dispersing evenly, place the dispersion in an oil bath, condense and reflux at 110° C. for 10 h, and then filter and dry to obtain modified carbon nanotubes.

[0038] The preparation method of the auxiliary agent is:

[0039] Sodium alginate and anhydrous ethanol were mixed in a mass ratio of 1:20, and 3-aminopropyltrimethoxysilane (0.3 times the mass of sodium alginate) was added. After stirring and mixing, 10% ammonia water (10% the mass of sodium alginate) was added dropwise. After reacting at 90° C. for 8 hours, tannic acid (0.2 times the mass of sodium alginate) was added. After ultrasonic dispersion treatment for 30 minutes, the mixture was filtered, dried, and added to BASF EfkaPU 4063 solution (14 times the mass of sodium alginate) and ultrasonic dispersion treatment was performed for 3 hours.

[0040] Example 2

[0041] A method for preparing an aqueous polyurethane resin with high heat resistance comprises the following steps:

[0042] S1. According to the weight of the raw materials, 8.7 parts of polycaprolactone diol, 25.4 parts of polytetrahydrofuran diol and 2.9 parts of 2,2-dimethylol propionic acid were added to the reactor in sequence, and dehydrated at 110° C. for 0.75 h;

[0043] S2. Under the protection of nitrogen, add 2.6 parts of auxiliary agent, cool to 75°C, add 10.6 parts of isophorone diisocyanate, 18.3 parts of hydrogenated phenylmethane diisocyanate, and 0.008 parts of dibutyltin dilaurate while stirring at 120 rpm, heat to 95°C, stir and react for 2.5 hours, add 10.8 parts of modified nanocarbon tubes, and keep warm to react until the -NCO content drops to 2.5%;

[0044] S3, cooling to below 50°C, adding 3.3 parts of hydrazine hydrate, stirring and dispersing at a high speed of 5000 rpm for 1.5 min, adding 102 parts of deionized water, stirring and dispersing at a high speed of 5000 rpm, and then chain extending with 2.5 parts of 3-hydroxymethylpropane in water, and finally irradiating at a radiation voltage of 115 kV, a radiation current of 1 mA, and a radiation dose of 75 KGy to obtain a waterborne polyurethane resin.

[0045] The preparation of the modified carbon nanotubes comprises the following steps:

[0046] (1) adding carbon nanotubes and lanthanum acetate in a ratio of 35:1 into a bead mill, grinding at a speed of 2500 rpm for 6 min, then adding into concentrated nitric acid, the volume ratio of carbon nanotubes to concentrated nitric acid being 3.5:1, stirring and mixing under ultrasonic conditions, heating and refluxing at 120° C. for 2 to 3 h, filtering, washing with deionized water 4 times, and drying to obtain a composite material for use;

[0047] (2) Add polyaspartic acid powder and water in a ratio of 1 g:10 mL into a beaker and mix well. Then add the composite material into the solution to make the concentration of the composite material 6 mg / mL. After stirring and dispersing evenly, the dispersion is placed in an oil bath, condensed and refluxed at 115°C for 11 hours, and then filtered and dried to obtain modified carbon nanotubes.

[0048] The preparation method of the auxiliary agent is:

[0049] Sodium alginate and anhydrous ethanol were mixed in a mass ratio of 1:25, and 3-aminopropyltrimethoxysilane (0.4 times the mass of sodium alginate) was added. After stirring and mixing, ammonia water (15% the mass of sodium alginate) was added dropwise. After reacting at 95° C. for 9 hours, tannic acid (0.25 times the mass of sodium alginate) was added. After ultrasonic dispersion treatment for 35 minutes, the mixture was filtered, dried, and added to BASF EfkaPU 4063 solution (16 times the mass of sodium alginate) and ultrasonic dispersion treatment was performed for 3.5 hours.

[0050] Example 3

[0051] A method for preparing an aqueous polyurethane resin with high heat resistance comprises the following steps:

[0052] S1. According to the weight of the raw materials, 9.2 parts of polycaprolactone diol, 27.4 parts of polytetrahydrofuran diol and 3.2 parts of 2,2-dimethylol propionic acid were added to the reaction kettle in sequence, and dehydrated at 120° C. for 1 hour;

[0053] S2. Under the protection of nitrogen, add 2.8 parts of auxiliary agent, cool to 80°C, add 11.4 parts of isophorone diisocyanate, 19.3 parts of hydrogenated phenylmethane diisocyanate, and 0.009 parts of dibutyltin dilaurate while stirring at 140rpm, heat to 99°C, stir and react for 3h, add 11.4 parts of modified nanocarbon tubes, and keep warm to react until the -NCO content drops to 2.5%;

[0054] S3, cooling to below 50°C, adding 3.5 parts of hydrazine hydrate, stirring and dispersing at a high speed of 8000 rpm for 2 minutes, adding 105 parts of deionized water, stirring and dispersing at a high speed of 8000 rpm, and then chain extending with 2.7 parts of 3-hydroxymethylpropane in water, and finally irradiating at a radiation voltage of 120 kV, a radiation current of 1 mA, and a radiation dose of 90 KGy to obtain a waterborne polyurethane resin.

[0055] The preparation of the modified carbon nanotubes comprises the following steps:

[0056] (1) adding carbon nanotubes and lanthanum acetate in a ratio of 50:1 into a bead mill, grinding at a speed of 3000 rpm for 8 min, then adding into concentrated nitric acid, the volume ratio of carbon nanotubes to concentrated nitric acid being 4:1, stirring and mixing under ultrasonic conditions, heating and refluxing at 130° C. for 2 to 3 h, filtering, washing with deionized water for 5 times, and drying to obtain a composite material for use;

[0057] (2) Add polyaspartic acid powder and water in a ratio of 1 g:10 mL into a beaker and mix well. Then add the composite material into the solution to make the concentration of the composite material 8 mg / mL. After stirring and dispersing evenly, place the dispersion in an oil bath, condense and reflux at 120° C. for 12 h, and then filter and dry to obtain modified carbon nanotubes.

[0058] The preparation method of the auxiliary agent is:

[0059] Sodium alginate and anhydrous ethanol were mixed in a mass ratio of 1:30, and 3-aminopropyltrimethoxysilane (0.5 times the mass of sodium alginate) was added. After stirring and mixing, 20% ammonia water (20% the mass of sodium alginate) was added dropwise. After reacting at 100° C. for 10 hours, tannic acid (0.3 times the mass of sodium alginate) was added. After ultrasonic dispersion treatment for 40 minutes, the mixture was filtered, dried, and added to BASF Efka PU 4063 solution (18 times the mass of sodium alginate) and ultrasonic dispersion treatment was performed for 4 hours.

[0060] Comparative Example 1

[0061] On the basis of Example 2, the modified carbon nanotubes are replaced with unmodified carbon nanotubes, and the rest of the technical solutions are consistent with those of Example 2.

[0062] Comparative Example 2

[0063] On the basis of Example 2, no modified nano carbon tubes are added, and the rest of the technical solutions are consistent with those of Example 2.

[0064] Comparative Example 3

[0065] On the basis of Example 2, no auxiliary agent is added, and the rest of the technical scheme is consistent with the technical scheme of Example 2.

[0066] Comparative Example 4

[0067] On the basis of Example 2, no irradiation treatment is performed, and the rest of the technical solutions remain consistent with the technical solutions of Example 2.

[0068] test

[0069] 1. Resin mechanical properties test

[0070] The sample was prepared according to GB / T 528-2009, the test temperature was about 25°C, and the tensile rate was 100 mm / min.

[0071] The test results are shown in Table 1 below.

[0072] Table 1 Mechanical properties of resins in various embodiments and comparative examples

[0073] Tensile strength / MPa Elongation at break / % Example 1 39.5 768.26 Example 2 41.8 898.35 Example 3 42.0 876.35 Comparative Example 1 36.5 624.58 Comparative Example 2 27.8 498.34 Comparative Example 3 38.2 708.37 Comparative Example 4 39.0 735.69

[0074] As can be seen from Table 1, the waterborne polyurethane resins prepared in Examples 1 to 3 of the present invention have excellent performance in tensile strength and elongation at break. From the comparison of the test data of Examples 1 to 3 and Comparative Examples 1 to 4, it can be found that Examples 1 to 3 have obvious advantages in tensile strength and elongation at break, which shows that the cooperation of modified nano-carbon tubes, the addition of additives and irradiation treatment significantly improves the mechanical properties of the waterborne polyurethane resin.

[0075] 2. Resin TG test:

[0076] N2 atmosphere, measuring range: 25~700℃, heating rate: 10℃ / min.

[0077] The test results are shown in Table 2 below.

[0078] Table 2 Thermal stability of resins in various examples and comparative examples

[0079]

[0080]

[0081] As can be seen from Table 2, the waterborne polyurethane resins prepared in Examples 1 to 3 of the present invention have significant advantages in initial pyrolysis temperature, maximum degradation rate temperature difference and residual carbon rate, which shows that the cooperation of modified carbon nanotubes, the addition of additives and irradiation treatment can greatly improve the heat resistance of waterborne polyurethane resins.

[0082] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A waterborne polyurethane resin with high heat resistance, characterized in that: The raw materials for preparing the waterborne polyurethane resin with high heat resistance include the following components in parts by mass: 8.2-9.2 parts of polycaprolactone diol, 23.4-27.4 parts of polytetrahydrofuran diol, 9.8-11.4 parts of isophorone diisocyanate, 17.3-19.3 parts of hydrogenated phenylmethane diisocyanate, 2.6-3.2 parts of 2,2-dihydroxymethylpropionic acid, 2.1-2.7 parts of 3-hydroxymethylpropane, 10.2-11.4 parts of modified nano carbon tubes, 2.4-2.8 parts of auxiliary agent, 3.1-3.5 parts of hydrazine hydrate, 0.007-0.009 parts of dibutyltin dilaurate, and 99-105 parts of deionized water.

2. The waterborne polyurethane resin with high heat resistance according to claim 1, characterized in that: The preparation of the modified carbon nanotubes comprises the following steps: (1) adding carbon nanotubes and lanthanum acetate in a ratio of 20 to 50:1 into a bead mill, grinding at a speed of 2000 to 3000 rpm for 4 to 8 minutes, then adding into concentrated nitric acid, stirring and mixing under ultrasonic conditions, heating and refluxing for 2 to 3 hours, filtering, washing with deionized water for 3 to 5 times, and drying to obtain a composite material for use; (2) Add polyaspartic acid powder and water in a ratio of 1 g:10 mL into a beaker and mix well. Then add the composite material into the solution, stir and disperse evenly, place the dispersion in an oil bath, condense and reflux at 110-120° C. for 10-12 h, and then filter and dry to obtain modified carbon nanotubes.

3. The waterborne polyurethane resin with high heat resistance according to claim 2, characterized in that: The volume ratio of the carbon nanotubes to the concentrated nitric acid in step (1) is 3-4:1, and the heating reflux temperature is 110-130°C.

4. The waterborne polyurethane resin with high heat resistance according to claim 2, characterized in that: The concentration of the composite material in the dispersion described in step (2) is 4-8 mg / mL.

5. The waterborne polyurethane resin with high heat resistance according to claim 1, characterized in that: The preparation method of the auxiliary agent is: Sodium alginate and anhydrous ethanol are mixed evenly in a mass ratio of 1:20-30, and 3-aminopropyltrimethoxysilane in an amount of 0.3-0.5 times the mass of sodium alginate is added. After stirring and mixing, ammonia water is added dropwise. After reacting at 90-100° C. for 8-10 hours, tannic acid in an amount of 0.2-0.3 times the mass of sodium alginate is added. After ultrasonic dispersion treatment for 30-40 minutes, the mixture is filtered, dried, and added to BASF EfkaPU 4063 solution, and ultrasonic dispersion treatment is performed for 3-4 hours.

6. The waterborne polyurethane resin with high heat resistance according to claim 5, characterized in that: The amount of ammonia water added is 10-20% of the mass of sodium alginate, and the amount of BASF EfkaPU 4063 solution added is 14-18 times of the mass of sodium alginate.

7. A method for preparing the waterborne polyurethane resin having high heat resistance according to any one of claims 1 to 6, characterized in that: The steps include: S1. Add polycaprolactone diol, polytetrahydrofuran diol and 2,2-dimethylol propionic acid into a reaction kettle in sequence according to the weight of the raw materials, and dehydrate at 100-120° C. for 0.5-1 h; S2. Under the protection of nitrogen, add the auxiliary agent, cool to 70-80°C, add isophorone diisocyanate, hydrogenated phenylmethane diisocyanate, and dibutyltin dilaurate while stirring, heat to 90-99°C, stir and react for 2-3 hours, add the modified nano-carbon tubes, and keep the temperature to react until the -NCO content is reduced to 2.5%; S3. Cool down to below 50°C, add hydrazine hydrate, stir and disperse at high speed for 1 to 2 minutes, then add deionized water and stir and disperse evenly at high speed, then use 3-hydroxymethylpropane to extend the chain in water, and finally irradiate at a radiation voltage of 110 to 120 kV, a radiation current of 1 mA, and a radiation dose of 60 to 90 KGy to obtain a waterborne polyurethane resin.

8. The waterborne polyurethane resin with high heat resistance according to claim 7, characterized in that: The stirring speed of adding while stirring in step S2 is 100-140 rpm.

9. The waterborne polyurethane resin with high heat resistance according to claim 7, characterized in that: The stirring speed of the high-speed stirring and dispersing in step S3 is 3000-8000 rpm.

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