CN115819823B - Preparation method, product and application of water-lubricated nitrile rubber surface polymer brush - Google Patents

Abstract

The invention discloses a preparation method of a water-lubricated nitrile rubber surface polymer brush, which comprises the following steps: s1, preparing nitrile rubber compound by adopting a mechanical blending method; s2, performing vulcanization molding on the nitrile rubber compound prepared in the step S1 to obtain vulcanized nitrile rubber; s3, placing the vulcanized nitrile rubber in excessive polyisocyanate with terminal NCO groups, reacting to obtain a product with the terminal NCO groups covered on the surface, taking out and centrifuging the product, wiping the product in nitrogen or inert atmosphere, and placing the product in excessive polyol subjected to decompression and water removal to react to obtain the water-lubricated nitrile rubber surface polymer brush. The invention also discloses a corresponding product and application. The invention accurately finds out the reactive sites on the NBR surface, provides possibility for chemical surface grafting of the rubber, solves the problem of poor surface hydrophilicity of the vulcanized nitrile rubber in the prior art, and improves the water lubrication tribological performance of the vulcanized nitrile rubber.

Description

Preparation methods, products and applications of water-lubricated nitrile rubber surface polymer brushes

Technical field

The invention belongs to the technical field of polymer materials, and specifically relates to a preparation method, product and application of a nitrile rubber surface polymer brush with excellent water lubricating tribological properties.

Background technique

Nitrile butadiene rubber (NBR) is widely used in the field of water-lubricated bearings because of its excellent tribological properties, good sediment tolerance, and vibration damping properties. However, under heavy load and low speed conditions, it is difficult for nitrile rubber bearings to completely form a hydrodynamic film between the bearing and the shaft. Some areas are in a state of boundary lubrication or even dry friction, resulting in severe wear and vibration noise, which reduces the durability of the ship's shaft system. safety and longevity, while also bringing hidden dangers to the stealth performance of underwater vehicles.

Relevant studies have shown that materials with strong hydrophilicity are conducive to the formation of water films, thereby having better water lubrication properties and lower vibration noise. Therefore, scholars try to hydrophilically modify polymer materials to obtain better performance. Excellent water lubricating tribological properties. Among them, polymer brush (chemical graft modification) is a polymerization reaction of monomers at the initiation point on the polymer surface to form an ordered chain layer, forming a thin film. The grafted layer can be highly stretched in the corresponding lubricant. The formation of a hydration layer greatly reduces the shear strength, and the interchain molecules have strong osmotic pressure repulsion and can carry higher loads, providing excellent lubrication effects.

However, in the existing technology, polymer brushes are mainly synthesized on the surface of membranes or fabrics, and their tribological properties in specific lubricating fluids are studied. However, water-lubricated bearings have high requirements on the mechanical properties of materials, and surface-grafted polymer brushes have little impact on them. Therefore, how to find chemically active sites on the surface of vulcanized rubber and successfully graft hydrophilic segments to its surface has become a research difficulty and a key technology.

Contents of the invention

In view of one or more of the above defects or improvement needs of the prior art, the present invention provides a preparation method, product and application of a water-lubricated nitrile rubber surface polymer brush, which accurately finds the reactive sites on the NBR surface. This provides the possibility of chemical surface grafting of this type of rubber, while solving the problem of poor surface hydrophilicity of vulcanized nitrile rubber in the prior art, and improving its water-lubricating tribological properties.

In order to achieve the above object, according to the first aspect of the present invention, a method for preparing a water-lubricated nitrile rubber surface polymer brush is provided, which includes the following steps:

S1 uses mechanical blending method to prepare nitrile rubber compound;

S2 vulcanizes the nitrile rubber compound prepared in step S1 to obtain vulcanized nitrile rubber;

S3: Place the vulcanized nitrile rubber in an excess of polyisocyanate with terminal NCO groups, and react to obtain a product whose surface is covered with terminal NCO groups. Take it out, centrifuge it, wipe it dry in nitrogen or an inert atmosphere, and place it side by side. The water-lubricated nitrile rubber surface polymer brush is obtained by reacting in the polyol after excess dehydration under reduced pressure.

As a further improvement of the present invention, in step S3, the reaction conditions of the vulcanized nitrile rubber and polyisocyanate are: reaction temperature 50°C to 70°C, rotor speed 200rpm to 500rpm, reaction time 20min to 40min.

As a further improvement of the present invention, in step S3, the reaction conditions of the product with terminal NCO groups on the surface and the polyol are: reaction temperature 70°C ~ 100°C, oil bath heating; rotor speed 400rpm ~ 600rpm, reaction time 2h～4h.

As a further improvement of the present invention, in step S3, the polyisocyanate includes one or more of hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, and isophorone diisocyanate.

As a further improvement of the present invention, in step S3, the polyol includes one or more of polyethylene glycol, polyphenylene ether, polyethylene oxide, polycaprolactone, and polybutyl acrylate.

As a further improvement of the present invention, in step S1, the nitrile rubber compound includes 100 parts of nitrile rubber, 4 to 7 parts of zinc oxide, 1 to 2 parts of stearic acid, 3 to 6 parts of antioxidant, and phthalate. 1 to 4 parts of dioctyl dicarboxylate, 0.5 to 1 part of sulfur, 1 to 3 parts of accelerator, and 40 to 60 parts of carbon black.

As a further improvement of the present invention, in step S2, the preparation conditions of the vulcanized nitrile rubber are determined based on the vulcanization curve measured from the nitrile rubber compound; preferably, the reaction temperature is 100°C ~ 200°C, and the specific pressure is 10~ 30Mpa, time is 20~50min.

As a further improvement of the present invention, in step S2, a tablet press is used to vulcanize the nitrile rubber.

According to a second aspect of the present invention, a water-lubricated nitrile rubber surface polymer brush is provided, which is prepared according to the preparation method.

According to a third aspect of the present invention, an application of the water-lubricated nitrile rubber surface polymer brush as a water-lubricated bearing material is provided.

Generally speaking, compared with the prior art, the above technical solution conceived by the present invention has the following beneficial effects:

In the present invention, a polyisocyanate intermediate containing terminal NCO reactive groups is introduced, and an active hydrogen transfer reaction occurs with the acrylonitrile cyano group on the surface of NBR to generate an amide structure, and then the polyol is used to carry out the other terminal NCO group of the polyisocyanate intermediate. End-capping, preparing a polymer brush containing hydrophilic segments on the surface, accurately finding the reactive sites on the NBR surface, providing the possibility of chemical surface grafting of this type of rubber, and at the same time solving the problems of vulcanized nitrile rubber in the existing technology The problem of poor surface hydrophilicity improves its water lubricating tribological properties.

Description of the drawings

Figure 1 is an SEM image of a polymer brush on the surface of nitrile rubber in Example 1 of the present invention;

Figure 2 is an SEM image of the nitrile rubber surface after wear by the polymer brush in Example 1 of the present invention.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

The preparation method of the water-lubricated nitrile rubber surface polymer brush of the present invention includes the following steps:

S1 uses mechanical blending method to prepare nitrile rubber compound;

S2 vulcanizes the nitrile rubber compound prepared in step S1 to obtain vulcanized nitrile rubber;

S3 Place the vulcanized nitrile rubber in an excess of polyisocyanate with terminal NCO groups. The reaction will produce a product whose surface is covered with terminal NCO groups. Take it out, centrifuge it, dry it in nitrogen or an inert atmosphere, and place it in an excess amount of polyisocyanate. The final product is obtained by reacting in the polyol after removing water under reduced pressure, which is a water-lubricated nitrile rubber surface polymer brush.

Specifically, in step S1, the nitrile rubber compound includes 100 parts of nitrile rubber, 4 to 7 parts of zinc oxide, 1 to 2 parts of stearic acid, 3 to 6 parts of antioxidant, and dioctyl phthalate. 1 to 4 parts of ester, 0.5 to 1 part of sulfur, 1 to 3 parts of accelerator, and 40 to 60 parts of carbon black.

It should be noted that the antioxidant and accelerator can be rubber antioxidants and accelerators in the prior art. In the preferred embodiment of the present invention, the antioxidant NA and the accelerator DM are selected. In addition, the formula materials of nitrile rubber compound are all commercially available.

In addition, the mechanical blending method is to add raw rubber to the open mill, wait for it to be rolled, add activator, carbon black, plasticizer and antioxidant in order, mix evenly, add vulcanizing agent and accelerator, and mix again After uniformity, thin it out, cut into slices, leave it for 24 hours and then return to refining. The mechanical blending method is a commonly used mixing method in the prior art and will not be described in detail here.

In step S2, the preparation conditions of the vulcanized nitrile butadiene rubber are determined based on the vulcanization curve of the nitrile butadiene rubber compound. It is preferred to use a rubber processing analyzer to test the vulcanization curve _. In a preferred embodiment, the reaction temperature is 100°C to 200°C, the specific pressure is 10 to 30Mpa, and the reaction time is 20 to 50 minutes.

In step S3, the reaction conditions of vulcanized nitrile rubber and polyisocyanate are: reaction temperature 50°C to 70°C, rotor speed 200rpm to 500rpm, reaction time 20min to 40min.

Further, in step S3, the reaction conditions of the product with terminal NCO groups on the surface and the polyol are: reaction temperature 70°C to 100°C, oil bath heating; rotor speed 400rpm to 600rpm, reaction time 2h to 4h.

Preferably, the polyisocyanate includes one or more of hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and isophorone diisocyanate (IPDI).

Preferably, the polyol includes one or more of polyethylene glycol (PEG), polyphenylene ether (PPO), polyethylene oxide (PEO), polycaprolactone (PCL), and polybutyl acrylate (PBA). .

In addition, the inert atmosphere includes helium, neon, argon, krypton, xenon, etc.; nitrogen is preferably used.

The invention provides a preparation process that is simple and can effectively improve the water lubricating tribological properties of nitrile rubber. Using a nitrile rubber matrix, an active hydrogen transfer reaction occurs with a polyisocyanate with terminal NCO groups, and then a polyol is used to cap the other terminal NCO group of the polyisocyanate to prepare a polymer brush with hydrophilic segments on the surface. The reactive sites on the surface of NBR have been accurately found, which provides the possibility for chemical surface grafting of this type of rubber. At the same time, it solves the problem of poor surface hydrophilicity of vulcanized nitrile rubber in the existing technology and improves its water-lubricated friction. academic performance.

In order to better illustrate and understand the technical solution of the present invention, the following specific examples are provided:

Example 1

(1) Use mechanical blending method to prepare nitrile rubber compound. The formula is as follows: 100 parts of nitrile rubber, 5 parts of zinc oxide, 2 parts of stearic acid, 4 parts of antioxidant, and 2 parts of dioctyl phthalate. , 1 part sulfur, 2 parts accelerator, 50 parts carbon black;

(2) Store the mixed rubber at room temperature for 24 hours, test its vulcanization curve and determine the vulcanization conditions. Set the temperature to 160°C, the specific pressure to 20Mpa, and the time to 30 minutes. Select 16.5mm×6.5mm×10mm on the tablet press. The mold vulcanizes nitrile rubber;

(3) Place the vulcanized nitrile rubber in a flask containing 50 mL of hexamethylene diisocyanate, set the temperature to 60°C, the rotor speed to 400 rpm, and react for 30 minutes to obtain a product whose surface is covered with terminal NCO groups. Take it out and centrifuge it, then wipe it dry in a nitrogen atmosphere, then put it into a three-necked flask containing 50 mL of polyethylene glycol that has been dehydrated under reduced pressure, heat it in an 80°C oil bath, stir at 500 rpm, and react for 3 hours to obtain the final product. .

Example 2

(1) Use mechanical blending method to prepare nitrile rubber compound. The formula is as follows: 100 parts of nitrile rubber, 6 parts of zinc oxide, 2 parts of stearic acid, 3 parts of antioxidant, and 2 parts of dioctyl phthalate. , 0.5 parts of sulfur, 2 parts of accelerator, 40 parts of carbon black;

(2) Store the mixed rubber at room temperature for 24 hours, test its vulcanization curve and determine the vulcanization conditions. Set the temperature to 180°C, the specific pressure to 10Mpa, and the time to 40 minutes. Select 16.5mm×6.5mm×10mm on the tablet press. The mold vulcanizes nitrile rubber;

(3) Place the vulcanized nitrile rubber in a flask containing 50 mL of toluene diisocyanate, set the temperature to 50°C, the rotor speed to 250 rpm, and react for 40 minutes to obtain a product whose surface is covered with terminal NCO groups. Take it out and centrifuge it, then wipe it dry in a nitrogen atmosphere, then put it into a three-necked flask containing 50 mL of polyphenylene ether that has been dehydrated under reduced pressure, heat it in an oil bath at 70°C, stir at 500 rpm, and react for 4 hours to obtain the final product.

Example 3

(1) Use mechanical blending method to prepare nitrile rubber compound. The formula is as follows: 100 parts of nitrile rubber, 4 parts of zinc oxide, 1 part of stearic acid, 3 parts of antioxidant, and 1 part of dioctyl phthalate. , 1 part of sulfur, 3 parts of accelerator, 60 parts of carbon black;

(2) Store the mixed rubber at room temperature for 24 hours, test its vulcanization curve and determine the vulcanization conditions. Set the temperature to 200°C, the specific pressure to 20Mpa, and the time to 20 minutes. Select 16.5mm×6.5mm×10mm on the tablet press. The mold vulcanizes nitrile rubber;

(3) Place the vulcanized nitrile rubber in a flask containing 50 mL of diphenylmethane diisocyanate, set the temperature to 60°C, the rotor speed to 500 rpm, and react for 25 minutes to obtain a product whose surface is covered with terminal NCO groups. Take it out and centrifuge it, then wipe it dry in a nitrogen atmosphere, then put it into a three-necked flask containing 50 mL of polyethylene oxide that has been dewatered under reduced pressure, heat it in an oil bath at 100°C, stir at 600 rpm, and react for 2 hours to obtain the final product.

Example 4

(1) Use mechanical blending method to prepare nitrile rubber compound, the formula is as follows: 100 parts of nitrile rubber, 7 parts of zinc oxide, 2 parts of stearic acid, 5 parts of antioxidant, 3 parts of dioctyl phthalate , 1 part sulfur, 3 parts accelerator, 50 parts carbon black;

(2) Store the mixed rubber at room temperature for 24 hours, test its vulcanization curve and determine the vulcanization conditions. Set the temperature to 100°C, the specific pressure to 20Mpa, and the time to 50 minutes. Select 16.5mm×6.5mm×10mm on the tablet press. The mold vulcanizes nitrile rubber;

(3) Place the vulcanized nitrile rubber in a flask containing 50 mL of isophorone diisocyanate, set the temperature to 70°C, the rotor speed to 300 rpm, and react for 20 minutes to obtain a product whose surface is covered with terminal NCO groups. Take it out and centrifuge it, then wipe it dry in a nitrogen atmosphere, and then put it into a three-necked flask containing 50 mL of polybutyl acrylate that has been dehydrated under reduced pressure. Heat it in a 90°C oil bath, stir at 500 rpm, and react for 3 hours to obtain the final product. .

Example 5

(1) Use mechanical blending method to prepare nitrile rubber compound. The formula is as follows: 100 parts of nitrile rubber, 5 parts of zinc oxide, 2 parts of stearic acid, 6 parts of antioxidant, and 4 parts of dioctyl phthalate. , 1 part sulfur, 1 part accelerator, 50 parts carbon black;

(2) Store the mixed rubber at room temperature for 24 hours, test its vulcanization curve and determine the vulcanization conditions. Set the temperature to 160°C, the specific pressure to 20Mpa, and the time to 30 minutes. Select 16.5mm×6.5mm×10mm on the tablet press. The mold vulcanizes nitrile rubber;

(3) Place the vulcanized nitrile rubber in a flask containing 50 mL of hexamethylene diisocyanate, set the temperature to 60°C, the rotor speed to 200 rpm, and react for 35 minutes to obtain a product whose surface is covered with terminal NCO groups. Take it out and centrifuge it, then wipe it dry in a nitrogen atmosphere, then put it into a three-necked flask containing 50 mL of polyphenylene ether that has been dehydrated under reduced pressure, heat it in an 80°C oil bath, stir at 400 rpm, and react for 3 hours to obtain the final product.

Example 6

(1) Use mechanical blending method to prepare nitrile rubber compound. The formula is as follows: 100 parts of nitrile rubber, 5 parts of zinc oxide, 1 part of stearic acid, 5 parts of antioxidant, and 2 parts of dioctyl phthalate. , 1 part sulfur, 2 parts accelerator, 50 parts carbon black;

(2) Store the mixed rubber at room temperature for 24 hours, test its vulcanization curve and determine the vulcanization conditions. Set the temperature to 160°C, the specific pressure to 20Mpa, and the time to 30 minutes. Select 16.5mm×6.5mm×10mm on the tablet press. The mold vulcanizes nitrile rubber;

(3) Place the vulcanized nitrile rubber in a flask containing 50 mL of toluene diisocyanate, set the temperature to 60°C, the rotor speed to 250 rpm, and react for 30 minutes to obtain a product whose surface is covered with terminal NCO groups. Take it out and centrifuge it, then wipe it dry in a nitrogen atmosphere, then put it into a three-necked flask containing 50 mL of polyethylene glycol that has been dehydrated under reduced pressure, heat it in an 80°C oil bath, stir at 500 rpm, and react for 3 hours to obtain the final product. .

Characterization and performance testing of the nitrile rubber matrix and the nitrile rubber surface-grafted with polymer brushes in Example 1 are provided, and the following test examples are provided:

Test example 1

A scanning electron microscope (SEM) was used to observe the surface of the nitrile rubber material grafted with polymer brushes. As shown in Figure 1, the polyol polymer brushes were evenly arranged and formed a continuous film on the surface of the nitrile rubber.

Test example 2

Water contact angle test; the water contact angle of the sample is based on GB/T 30693-2014, using the OCA-25 water contact angle measuring instrument, and selecting 10 nitrile rubber substrates and nitrile rubber with polymer brushes grafted on the surface. Test at different locations and calculate the average of the test results. The results are shown in Table 1.

Table 1 Water contact angle of materials

Material Water contact angle (°) Nitrile rubber matrix 103.95 Nitrile rubber with surface grafted polymer brush 72.04

The results show that the water contact angle of the polymer brush is significantly reduced and less than 90°, and the hydrophilicity of the material is improved.

Test example 3

Friction and wear performance test: UMT-TL friction testing machine is used for testing. After installing the sample, conduct a ring-block friction and wear test. The size of the plastic standard sample is 16.5mm × 6.5mm × 10mm. The material of the ground tin bronze ring is ZCuSn10Zn2, the size is Φ35.00mm × 8.75mm, and the loading force is set to 100N. The rotation speed is 100N. They are 0.045, 0.090, 0.180, 0.270, 0.360, 0.540, 0.900, 1.500, 1.800m/s respectively, and the friction time is 600s.

The results show that the friction coefficient of nitrile rubber with polymer brush grafted on the surface is significantly reduced under water lubrication conditions, and the lubrication state is more stable, as shown in Table 2.

Table 2 Friction coefficient of materials under water lubrication conditions

Speed(m/s) Nitrile rubber matrix Nitrile rubber with surface grafted polymer brush 0.045 0.24158 0.12304 0.090 0.31435 0.18955 0.180 0.6305 0.22998 0.270 0.52185 0.13864 0.360 0.38629 0.1014 0.540 0.24942 0.08817 0.900 0.15413 0.04715 1.500 0.09339 0.03723 1.800 0.08727 0.03313

Furthermore, a scanning electron microscope (SEM) was used to observe the wear surface morphology of the material. The results are shown in Figure 2. Most areas of the surface of the grafted polymer brushed nitrile rubber are relatively smooth, and almost no microscopic wear behavior occurs.

Test example 4

Collection of friction vibration signals: implemented using the Pulse system, 4519 vibration acceleration sensor, and 3676 module. A B&K4519 sensor is arranged above the friction base of the testing machine. This sensor can record the vibration above the tangential direction of the friction surface. By connecting to the 3676 module, the friction vibration acceleration signal of the sample block is stored. MATLAB software is used in the computer. Perform analysis. Collect the vibration signals from 296s to 305s of the friction test, and take the 300s signal for analysis. The collection frequency is 65536Hz.

The results are shown in Table 3. The total vibration level of friction vibration of nitrile rubber grafted with polymer brushes on the surface under water lubrication conditions is reduced to varying degrees, and it has lower vibration energy.

Table 3 Total vibration level (dB) of materials under water lubrication conditions

Speed(m/s) Nitrile rubber matrix Nitrile rubber with surface grafted polymer brush 0.045 97.968 97.758 0.090 98.624 97.945 0.180 104.591 102.291 0.270 113.585 108.284 0.360 118.281 116.243 0.540 123.28 119.717 0.900 127.751 125.635 1.500 133.187 131.852 1.800 134.245 132.838

In summary, by testing and analyzing the tribological conditions of rubber before and after surface modification in a water environment, it can be seen that the surface of nitrile rubber grafted with polymer brushes has a significantly lower water contact angle due to the grafting of hydrophilic segments. It has a lower friction coefficient, and microscopic wear has also been improved. The vibration energy is lower than that of nitrile rubber before modification to varying degrees, showing excellent vibration damping performance. The present invention provides an idea for applying molecular brush surface modification technology to water lubricating bearing materials, and provides a reliable basis for designing and preparing polymer materials with good water lubricating and vibration damping properties.

It is easy for those skilled in the art to understand that the above descriptions are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements, etc., made within the spirit and principles of the present invention, All should be included in the protection scope of the present invention.

Claims (10)

1. A method for preparing a water-lubricated nitrile rubber surface polymer brush, which is characterized in that it includes the following steps: S1 uses mechanical blending method to prepare nitrile rubber compound; S2 vulcanizes the nitrile rubber compound prepared in step S1 to obtain vulcanized nitrile rubber; S3: Place the vulcanized nitrile rubber in an excess of polyisocyanate with terminal NCO groups, and react to obtain a product whose surface is covered with terminal NCO groups. Take it out, centrifuge it, wipe it dry in nitrogen or an inert atmosphere, and place it side by side. The water-lubricated nitrile rubber surface polymer brush is obtained by reacting in the polyol after excess dehydration under reduced pressure. 2. The preparation method of the water-lubricated nitrile rubber surface polymer brush according to claim 1, characterized in that in step S3, the reaction conditions of the vulcanized nitrile rubber and polyisocyanate are: reaction temperature 50°C to 70°C ℃, rotor speed 200rpm ~ 500rpm, reaction time 20min ~ 40min. 3. The preparation method of the water-lubricated nitrile rubber surface polymer brush according to claim 1, characterized in that, in step S3, the reaction conditions of the product with terminal NCO groups on the surface and the polyol are: reaction The temperature is 70℃~100℃, heated by oil bath; the rotor speed is 400rpm~600rpm, and the reaction time is 2h~4h. 4. The preparation method of water-lubricated nitrile rubber surface polymer brush according to claim 1, characterized in that, in step S3, the polyisocyanate includes hexamethylene diisocyanate, toluene diisocyanate, and diphenylmethane. One or more of diisocyanate and isophorone diisocyanate. 5. The preparation method of water lubricated nitrile rubber surface polymer brush according to claim 1, characterized in that, in step S3, the polyol includes polyethylene glycol, polyphenylene ether, polyethylene oxide, polyhexane One or more of lactone and polybutyl acrylate. 6. The preparation method of the water-lubricated nitrile rubber surface polymer brush according to claim 1, characterized in that, in step S1, the nitrile rubber compound includes 100 parts of nitrile rubber and 4 to 7 parts of zinc oxide. 1 to 2 parts of stearic acid, 3 to 6 parts of antioxidant, 1 to 4 parts of dioctyl phthalate, 0.5 to 1 part of sulfur, 1 to 3 parts of accelerator, and 40 to 60 parts of carbon black. 7. The preparation method of the water-lubricated nitrile rubber surface polymer brush according to claim 1, characterized in that, in step S2, the preparation conditions of the vulcanized nitrile rubber are determined according to the vulcanization curve measured by the nitrile rubber compound. ;The reaction temperature is 100℃～200℃, the specific pressure is 10～30Mpa, and the time is 20～50min. 8. The method for preparing a water-lubricated nitrile rubber surface polymer brush according to claim 1, characterized in that, in step S2, a tablet press is used to vulcanize the nitrile rubber. 9. A water-lubricated nitrile rubber surface polymer brush, prepared according to the preparation method according to any one of claims 1-8. 10. Application of a water-lubricated nitrile rubber surface polymer brush as claimed in claim 9 as a water-lubricated bearing material.