Bionic lubricating composite material for water-lubricated tail bearing and preparation method thereof

Abstract

The application discloses a kind of water-lubricated tail bearing biomimetic lubricating composite material and preparation method thereof, with engineering polymer material as continuous phase, with polyelectrolyte polymer microparticle as dispersed phase;And polyelectrolyte polymer microparticle is evenly distributed in the interior of continuous phase with dot matrix structure, and is two-phase structure evenly distributed in space dot matrix.This application solves the problem of water-lubricated tail bearing lubrication failure under harsh working conditions caused by low water viscosity, and the composite material and its preparation method can improve the service performance, service life, reliability of ship tail bearing, and reduce long-term operation cost.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of bionic lubricating composite materials, and particularly relates to a bionic lubricating composite material for water-lubricated tail bearings and a preparation method thereof. BACKGROUND

[0002] The tail bearing is one of the most important components in the ship propulsion system, and its performance directly determines the reliability, safety and concealment of the ship navigation. According to the different lubrication modes, the ship tail bearing can be divided into oil-lubricated tail bearings and water-lubricated tail bearings. Due to the low reliability of the sealing element, the oil-lubricated tail bearing will inevitably cause lubricating oil leakage during use.

[0003] The water-lubricated tail bearing uses water as the lubricant. For example, the patent with the publication number CN103788623A discloses a water-lubricated bearing composed of synthetic polyurethane, solid lubricant and fiber reinforcing agent, which has high bearing capacity and self-lubricating property, and is widely used in underwater propeller motor drive, propeller shaft bearing, rudder bearing and water pump and other rotating or swinging sliding parts. It is a green ship tail bearing, and has many advantages such as good cooling performance, low use cost and the like. However, water has low viscosity, and under harsh working conditions such as heavy load and low speed, dry friction or semi-dry friction state is easy to occur, which leads to serious friction and wear, vibration and noise and the like. This problem limits the large-scale application of the water-lubricated tail bearing. The traditional marine powers such as Europe and the United States have been investing a large amount of manpower and material resources to study the lubrication performance of the water-lubricated tail bearing of the ship, and have proposed many research results and patents. However, the natural defect of low water viscosity still has no efficient and comprehensive solution.

[0004] Therefore, it is necessary to develop a bionic lubricating composite material for water-lubricated tail bearings to solve the technical problems caused by the low viscosity of water, so as to meet the development requirements of resource conservation, energy saving and emission reduction, ecological environment protection and national defense capability construction and the like, and has great social and economic benefits. SUMMARY

[0005] In order to overcome the problems existing in the prior art, the purpose of the present application is to provide a bionic lubricating composite material for water-lubricated tail bearings and a preparation method thereof, so as to completely solve the problem of lubrication failure of the water-lubricated tail bearing under harsh working conditions caused by the low viscosity of water. The composite material and the preparation method thereof can achieve the purpose of improving the service performance, service life, reliability and reducing the long-term operation cost of the ship tail bearing.

[0006] In order to achieve the above purpose, the technical scheme adopted by the present application is:

[0007] A kind of water-lubricated tail bearing is used to bionic lubricating composite material, with excellent wear resistance, water stability of engineering polymer material as continuous phase, with polyelectrolyte high molecular particle as dispersed phase with hydration lubrication effect;And polyelectrolyte high molecular particle is uniformly distributed in the interior of continuous phase with dot matrix structure, and the two-phase structure of spatial dot matrix is uniformly distributed.

[0008] Engineering polymer provides structural stability and bearing performance as matrix material, and polyelectrolyte particle provides bionic lubrication as dispersed phase.In the friction process, the matrix material maintains the stability of size and strength, and polyelectrolyte particle forms bionic lubricating layer by friction shear, crushing, and the comprehensive performance of ship stern bearing is improved based on the synergistic effect of the two.

[0009] The shape of the polyelectrolyte high molecular particle is irregular powder, the average particle size is between 5-500 μm, and the mass ratio in the engineering polymer material (continuous phase) is between 0.5-5%, to ensure the structural stability and long-term bionic lubrication performance of the composite material.

[0010] The engineering polymer material (continuous phase) is ultra-high molecular weight polyethylene (UHMWPE).

[0011] The polyelectrolyte high molecular particle is polyacrylamide (PAAm) hydrogel powder.

[0012] A kind of water-lubricated tail bearing is used to bionic lubricating composite material, with excellent wear resistance, water stability of engineering polymer material as continuous phase, with polyelectrolyte high molecular particle as dispersed phase with hydration lubrication effect;And polyelectrolyte high molecular particle is uniformly distributed in the interior of continuous phase with dot matrix structure, and the two-phase structure of spatial dot matrix is uniformly distributed.

[0013] Step 1: prepare multi-component reaction monomer aqueous solution according to certain proportion, place reaction monomer aqueous solution in airtight reaction container, exclude oxygen in container, heat to initiate polymerization, and obtain block polyelectrolyte hydrogel;The volume and weight of block hydrogel are determined by the size of reaction container;

[0014] Step 2: ultrasonic cleaning of the block polyelectrolyte hydrogel after polymerization in deionized water, mechanical crushing with crusher, to obtain hydrogel powder;Hydrogel powder is cleaned with deionized water and anhydrous ethanol alternately for several times, and then dried in vacuum drying oven at room temperature for 8h;Again, the dried hydrogel powder is crushed using a crusher, and the oversized particles are removed using a screen, to obtain dry hydrogel powder;

[0015] Step 3: put dry hydrogel powder and UHMWPE powder into high-speed mixer for pre-blending, then melt blend the pre-mixture for 15min using rubber-plastic mixing equipment, cool and crush to obtain the water-lubricated tail bearing bionic lubricating composite material.

[0016] In the step 1, the monomer solution is an aqueous solution containing acrylamide, N,N'-methylenebisacrylamide and ammonium persulfate, and the molar ratio of the three is 100:0.5:0.5.

[0017] In the step 1, the temperature is raised from room temperature to 80 DEG C to initiate the polymerization reaction.

[0018] In the step 2, the ultrasonic power used in the ultrasonic cleaning process is 60 W, and the ultrasonic time is 10 min.

[0019] In the step 2, the shape of the dried hydrogel powder is irregular particles, and the average particle size of the particles is between 0.5-100 mu m.

[0020] In the step 3, the mass ratio of the dried hydrogel powder to the UHMWPE powder is between 0.5% and 5%.

[0021] In the step 1, the closed reaction vessel is a reaction kettle with a vacuum pump and inert gas protection device.

[0022] The above-mentioned biomimetic lubricating composite material for water-lubricated tail bearing is used for the construction of a ship or an underwater vehicle.

[0023] The beneficial effects of the present application are:

[0024] The present application provides a polyelectrolyte macromolecular particle with biomimetic hydration lubrication effect, which is distributed in an engineering polymer matrix material in a dot matrix structure. When the biomimetic lubricating composite material is placed in a working environment, i.e. a water environment, due to the barrier effect of the engineering polymer matrix material on water molecules, the polyelectrolyte macromolecular particles in the composite material will not swell. Therefore, the composite material can maintain good dimensional and strength stability in the use environment; the polyelectrolyte macromolecular particles on the surface of the composite material can be sheared and broken into swollen hydrogel fragments with the relative movement of the friction pair, and the hydration lubricating layer composed of swollen hydrogel fragments has excellent load-carrying capacity and low shear characteristics, which can provide excellent biomimetic hydration lubrication for the two friction surfaces.

[0025] At the same time, with the occurrence of wear behavior, the polyelectrolyte macromolecular particles in the composite material are continuously ground to the surface and sheared and broken into hydrogel fragments to continuously supplement the lost hydrogel fragments in the friction process, ensuring the long-acting hydration lubrication of the composite material during the entire service life.

[0026] The engineering polymer is used as the matrix material, so that the size stability and bearing performance of the composite material can be effectively ensured; the polyelectrolyte microparticle is used as the lubricating component, so that the water lubrication performance of the composite material can be effectively improved. The bionic lubricating composite material for the water lubricating tail bearing guarantees the problem of lubrication failure of the water lubricating tail bearing under heavy load and low speed to be solved completely due to the lattice type composite structure and the special performance combination of the two components.

[0027] The bionic lubricating composite material for the water lubricating tail bearing has high-efficiency and stable underwater drag reduction effect, and has wide development prospect. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 The SEM morphology diagram of the random shape hydrogel microparticle is shown.

[0029] Figure 2 The SEM diagram and structure schematic diagram of the lattice type distribution of the hydrogel microparticle are shown.

[0030] Figure 3 The preparation process flow chart of the bionic lubricating composite material is shown. DETAILED DESCRIPTION

[0031] The application will be further described in detail below with reference to the drawings.

[0032] As shown in the formula (I), the embodiment 1 is prepared as follows: Figure 3

[0033] 1) N, N'-methylene bisacrylamide, ammonium persulfate and acrylamide are dissolved in a certain volume of deionized water according to the molar ratio of 0.5:0.5:100 to prepare a reaction monomer solution, and the polymerization reaction is initiated by heating to 80 DEG C to obtain a block-shaped PAAm hydrogel;

[0034] 2) The block-shaped PAAm hydrogel is broken into powder by a mechanical crushing method; the PAAm hydrogel powder is cleaned with deionized water and anhydrous ethanol alternately for 3 times by ultrasonic cleaning; then the dried PAAm hydrogel powder is mechanically crushed again by using a vacuum drying oven at room temperature for 8 hours; the particle size of the PAAm hydrogel microparticle is controlled to be 0.5-50 microns by using a 300 mesh screen;

[0035] 3) The PAAm hydrogel microparticle powder and the UHMWPE powder are put into a high-speed mixer according to the weight ratio of 0.5:100 to obtain a premix; the premix is put into a banbury mixer to be melt blended to obtain a block-shaped composite material; the block-shaped composite material is naturally cooled for 20 minutes, and then crushed by using a crusher to prepare the granular material of the bionic lubricating composite material;

[0036] ​4) The bionic lubricating composite material granular material is manufactured into a performance test sample of the bionic lubricating composite material for the ship stern bearing by using an injection molding or hot pressing method.

[0037] As shown in Figure 1 , Figure 2 , the prepared bionic lubricating composite material for the water-lubricated stern bearing is excellent in wear resistance and water immersion stability, and the engineering polymer material is used as the continuous phase, and the polyelectrolyte high molecular particle having the hydration lubrication effect is used as the dispersed phase. The polyelectrolyte high molecular particle is uniformly distributed in the continuous phase in a dot matrix structure, and the two-phase structure is uniformly distributed in space.

[0038] The engineering polymer is used as the matrix material to provide the structural stability and the bearing performance, and the polyelectrolyte particle is used as the dispersed phase to provide the bionic lubrication effect. In the friction process, the matrix material maintains the stability of the size and the strength, and the polyelectrolyte particle forms a bionic lubricating layer by friction shearing and crushing, and the comprehensive performance of the ship stern bearing is comprehensively improved based on the synergistic effect of the two.

[0039] The shape of the polyelectrolyte high molecular particle is irregular powder, the average particle size is between 5-500 μm, and the mass ratio in the engineering polymer material (continuous phase) is between 0.5-5%, so as to simultaneously ensure the structural stability and the long-acting bionic lubrication performance of the composite material.

[0040] Example 2

[0041] The performance test sample of Example 2 is manufactured by the steps 1), 2), 3), 4) of the example, wherein the weight ratio of the PAAm hydrogel particle powder and the UHMWPE powder in step 3) is adjusted to 1:100.

[0042] Example 3

[0043] The performance test sample of Example 3 is manufactured by the steps 1), 2), 3), 4) of the example, wherein the weight ratio of the PAAm hydrogel particle powder and the UHMWPE powder in step 3) is adjusted to 1.5:100. According to the following method, three kinds of water-lubricated stern bearings for ships are prepared, and the friction coefficient and the volume wear rate of each stern bearing are shown in Table 1.

[0044] Comparative Example 1

[0045] The UHMWPE powder is used as the manufacturing material, and the UHMWPE raw material performance test sample for the water-lubricated stern bearing is manufactured by step 4) of Example 1.

[0046] Comparative Example 2

[0047] The UHMWPE composite material reinforced by glass fiber was used as the manufacturing material to manufacture the composite material performance test sample for water-lubricated tail bearing through step 4) of Example 1.

[0048] Comparative Example 3

[0049] The UHMWPE composite material reinforced by carbon fiber was used as the manufacturing material to manufacture the composite material performance test sample for water-lubricated tail bearing through step 4) of Example 1.

[0050] According to the above method, the friction coefficients and volume wear rates of the six types of water-lubricated tail bearing materials of Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2 and Comparative Example 3 were tested respectively. In order to better simulate the actual operating conditions of the water-lubricated tail bearing, a copper ball and a polymer disc were used to form a friction pair for the friction and wear test. The diameter d of the copper ball was 10 mm, and the diameter d of the polymer disc was 20 mm and the thickness t was 6 mm. The MFT-5000 type friction and wear tester of Rtec Company was used for tribological performance test, the sliding speed was 100 mm / s, the maximum Hertz contact stress was 10.9 MPa, 18.7 MPa and 23.5 MPa respectively, each test was repeated 5 times, and the average value was taken. The friction coefficients of the optimal component allocation ratio of each material under the condition of water as lubricant are shown in Table 1.

[0051] Table 1 Friction coefficients of different materials

[0052]

[0053] By comparing and analyzing the friction coefficients in the table, it can be known that compared with the UHMWPE base material, the addition of PAAm hydrogel particles or carbon fibers can effectively reduce the friction coefficient of the UHMWPE base material, and the addition of glass fibers will cause the friction coefficient of the UHMWPE base material to rise. Among them, the friction coefficient of the composite material with a weight ratio of PAAm hydrogel particles to UHMWPE of 0.5:100 is the smallest, and the lubrication effect is the best.

[0054] In order to further verify the lubrication and wear reduction effect of PAAm hydrogel particles, the volume wear rates of the composite materials after the tribological performance test were further tested by laser confocal microscope. The volume wear rates of the optimal component allocation ratio of each material are shown in Table 2.

[0055] Table 2 Volume wear rates of different materials

[0056]

[0057]

[0058] By comparing the volume wear rate in the table, it can be seen that, compared with the UHMWPE matrix material, the addition of PAAm hydrogel particles or carbon fibers can effectively reduce the volume wear rate of UHMWPE, and the addition of glass fibers will cause the volume wear rate of UHMWPE to rise. Among them, the volume wear rate of the composite material with a PAAm hydrogel particle to UHMWPE weight ratio of 0.5:100 is the smallest, and the friction reduction effect is the best.

[0059] As can be seen from the above, the PAAm hydrogel particle / UHMWPE composite material for water-lubricated tail bearings has very excellent performance in water lubrication and friction reduction, and has broad application prospects.

Claims

1. A method for preparing a biomimetic lubricating composite material for a water-lubricated tail bearing, characterized in that, Includes the following steps: Step 1: Prepare a multi-component reactive monomer aqueous solution in a certain proportion, place the reactive monomer aqueous solution in a sealed reaction container, remove the oxygen in the container, raise the temperature to initiate polymerization, and obtain a block polyelectrolyte hydrogel. Step 2: The polymerized block polyelectrolyte hydrogel is ultrasonically cleaned in deionized water and mechanically crushed using a crusher to obtain hydrogel powder. The hydrogel powder is washed several times alternately with deionized water and anhydrous ethanol, and then dried in a vacuum drying oven at room temperature. The dried hydrogel powder is crushed again using a crusher, and oversized particles are removed using a sieve to obtain dried hydrogel powder. Step 3: The dry hydrogel powder and UHMWPE powder are put into a high-speed mixer for pre-mixing, and then the premixed material is melt-mixed, cooled and crushed to obtain the biomimetic lubrication composite material for water-lubricated tail bearing. The aqueous solution of the reaction monomer is an aqueous solution containing acrylamide, N,N'-methylenebisacrylamide, and ammonium persulfate, with a molar ratio of 100:0.5:0.

5. The biomimetic lubricating composite material for water-lubricated tail bearings obtained based on the above method uses engineering polymer materials as the continuous phase and polyelectrolyte polymer particles as the dispersed phase; and the polyelectrolyte polymer particles are uniformly distributed in a lattice structure inside the continuous phase, forming a two-phase structure with a spatially uniform lattice distribution. The polyelectrolyte polymer microparticles are irregularly shaped powders with an average particle size between 0.5 and 50 μm. The engineering polymer material is ultra-high molecular weight polyethylene (UHMWPE). The polyelectrolyte polymer particles are polyacrylamide (PAAm) hydrogel powder; The weight ratio of PAAm hydrogel microparticles to UHMWPE is 0.5:

100.

2. The method for preparing a biomimetic lubricating composite material for a water-lubricated tail bearing according to claim 1, characterized in that, In step 1, the heating process involves raising the temperature from room temperature to 80°C to initiate the polymerization reaction.

3. The method for preparing a biomimetic lubricating composite material for a water-lubricated tail bearing according to claim 1, characterized in that, In step 2, the ultrasonic cleaning process uses an ultrasonic power of 60W and an ultrasonic time of 10 minutes.

4. The biomimetic lubricating composite material for water-lubricated tail bearings obtained by the preparation method according to any one of claims 1-3, characterized in that, The biomimetic lubricating composite material for the water-lubricated stern bearing is used in the construction of ships or underwater vehicles.

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