A high polymer wear-resistant material and a preparation method thereof

Abstract

This invention relates to the field of polymer composite materials technology, and provides a polymer wear-resistant material and its preparation method. The material is made from the following raw materials: epoxy resin, ZIF-67@NiCo wear-resistant reinforcement containing coordination unsaturated sites, mussel-inspired multifunctional interface bridging agent containing dynamic covalent bonds, amino-terminated polydimethylsiloxane, curing agent, and additives. This invention constructs a closed-loop intelligent response system of friction triggering, in-situ catalysis, interface self-reinforcement, and lubrication self-replenishment: ZIF-67@NiCo functions as both a wear-resistant filler and an in-situ catalyst; the interface bridging agent contains dynamic disulfide bonds, and bond regeneration during crack propagation achieves interface self-repair; the amino-terminated PDMS re-bonds with the bridging agent under ZIF catalysis to achieve lubrication self-replenishment; the synergistic effect of these three components results in a coating adhesion ≥17MPa, a friction coefficient ≤0.12, wear amount ≤15mg / 1000r, and self-repair efficiency ≥80%, extending the coating life. The preparation process of this invention is simple, suitable for industrial production, and can be widely used in the inner surface protective layer of industrial equipment.

Description

Technical Field

[0001] This invention belongs to the field of polymer composite materials technology, specifically relating to a polymer wear-resistant material and its preparation method, which is suitable for wear-resistant protective layers on the inner surface of industrial equipment. Background Technology

[0002] In industrial sectors such as mining, cement, power, and ports, equipment such as hoppers, pipes, and silos are widely used in the mixing, transportation, and storage of materials. The inner surfaces of these devices are constantly subjected to the impact, wear, and corrosion of materials, which greatly reduces the service life of the overall structure. Therefore, it is necessary to install a protective layer on the inner surface to isolate the materials from direct contact with the equipment structure and protect the equipment.

[0003] Currently, commonly used protective layers include ceramic liners, rubber liners, and polymer wear-resistant coatings. Among them, polymer wear-resistant coatings are widely used due to their advantages such as convenient construction, low cost, and adaptability to complex shapes. However, traditional polymer wear-resistant coatings have the following technical defects: First, the interfacial bonding between the filler and the resin matrix is ​​weak, making it easy to peel off under high-load friction; second, the coating cannot self-repair after wear, and once microcracks appear, they will rapidly expand and lead to failure; third, the lubricant is easily lost, making it difficult to maintain long-term low-friction performance.

[0004] In recent years, researchers have attempted to introduce self-healing functions into coatings. For example, Chinese patent CN114989547B discloses a polymer composite material with in-situ wear repair function, which provides self-healing components for mating parts during friction by adding fillers such as layered silicates. However, this technology is mainly aimed at repairing mating parts and has limited repair capabilities for the coating itself. Other studies have reported self-healing coatings containing microcapsules. After the microcapsules rupture, they release repair agents to fill cracks. However, the interfacial compatibility between the microcapsules and the substrate is poor, and the repair agents cannot be sustained after being consumed once.

[0005] Metal-organic framework (MOF) materials, such as ZIF-67, have attracted attention in catalysis, energy storage and other fields due to their high specific surface area and tunable pore structure. However, ZIF materials are generally considered unsuitable for wear-resistant coatings in friction-generated scenarios due to their poor thermal stability (typically decomposing above 300°C). The local high temperatures (up to 200-300°C) generated during friction will cause ZIF decomposition, which is considered a negative factor. At the same time, no one in the existing technology has ever attempted to use the unsaturated sites on the ZIF surface to achieve in-situ catalytic regeneration of lubricants, and the technical challenge of synergistic wear resistance and self-repair of coatings has not been solved.

[0006] Therefore, developing a smart responsive polymer wear-resistant material that can achieve multi-level self-healing of the coating and regenerative lubrication has significant industrial application value. Summary of the Invention

[0007] This invention provides a polymer wear-resistant material and its preparation method, aiming to solve the problems of existing polymer wear-resistant coatings having single function, limited repair ability, easy loss of lubricant, and poor synergy among components.

[0008] This invention is achieved by providing a polymeric wear-resistant material and its preparation method, which is prepared from the following raw materials in parts by weight: 100 parts epoxy resin; 5-20 parts of a bimetallic organic framework wear-resistant reinforcement containing coordination unsaturated sites; 2-10 parts of a mussel-inspired multifunctional interface bridging agent containing dynamic covalent bonds; 5-15 parts of amino-terminated polydimethylsiloxane; 20-40 parts of curing agent; 0-2 parts of auxiliary agent; The wear-resistant reinforcement containing coordinating unsaturated sites of the bimetallic organic framework is a ZIF-67@NiCo nanocrystal synthesized by regulating the molar ratio of metal ions to organic ligands and having residual coordinating unsaturated metal sites on its surface; the mussel-inspired multifunctional interface bridging agent containing dynamic covalent bonds is a block copolymer synthesized from dopamine, chitosan, a crosslinking agent containing dynamic covalent bonds, and a silane coupling agent; the molecular weight of the amino-terminated polydimethylsiloxane is 2000-6000.

[0009] Preferably, in the bimetallic organic framework wear-resistant reinforcement containing coordination unsaturated sites, the molar ratio of metal ions to organic ligands is 1:2.5-1:3.5, and the ZIF-67@NiCo has a particle size of 300nm-1.5μm and a specific surface area ≥1000m². 2 / g; X-ray photoelectron spectroscopy (XPS) characterization revealed that the Ni on the ZIF-67@NiCo surface... 2+ / Co 2+ The density of coordination unsaturated sites is 0.8-1.2 per nm. 2 Fourier transform infrared (FT-IR) at 1580 cm⁻¹ -1 The characteristic peak shift of the imidazole ligand was observed at the site, confirming the existence of the coordination unsaturation site.

[0010] By controlling the molar ratio of metal ions to organic ligands to 1:2.5-1:3.5, ZIF-67@NiCo nanocrystals with residual coordinating unsaturated metal sites on the surface were synthesized. This reinforcement combines the dual functions of a high-hardness, wear-resistant filler and an in-situ catalyst. Thermogravimetric analysis (TGA) showed that ZIF-67@NiCo began to decompose slightly at 200℃, and the decomposition rate was 15-20% at 300℃. In-situ X-ray diffraction (XRD) tests indicated that this decomposition was only a dissociation of the surface framework, while the internal crystal structure remained intact, and the wear-resistant reinforcement effect was not lost. Furthermore, at 200-300℃, each gram of ZIF-67@NiCo could release 0.08-0.12 mmol / g of Ni. 2+ / Co 2+ The ions (calculated based on the amount of ZIF added in the coating, with a final concentration of 0.01-0.02 mol / L in the coating) can partially decompose under frictional heat (200-300℃), releasing Ni. 2+ / Co 2+ Ions form a wear-resistant transfer film, and their coordination unsaturated sites can catalyze the rebonding reaction of PDMS chain scission; this invention takes the opposite approach, transforming the traditionally considered unfavorable ZIF thermal decomposition characteristics into a controllable sacrificial intelligent response mechanism.

[0011] Preferably, in the mussel-inspired multifunctional interface bridging agent containing dynamic covalent bonds, the dynamic covalent bonds are selected from disulfide bonds or Schiff base bonds; the crosslinking agent containing dynamic covalent bonds is selected from 2,2'-dithiodiethylamine, 4,4'-dithiodiphenylamine or dithiodipropionic acid; and the crosslinking agent containing dynamic covalent bonds accounts for 5-20% of the total mass of the bridging agent.

[0012] Using dopamine, chitosan, a crosslinking agent containing dynamic covalent bonds (disulfide bonds), and a silane coupling agent as raw materials, a block copolymer containing catechol groups, amino groups, siloxane structures, and dynamic covalent bonds was synthesized. This bridging agent has three functions: strong adhesion between catechol groups and metal substrates; chemical crosslinking between amino groups and epoxy resins; and preferential breakage of dynamic disulfide bonds during microcrack propagation, exposing new active sites and achieving interface self-reinforcement.

[0013] Preferably, the amino-terminated polydimethylsiloxane has a molecular weight of 3000-5000 and an amino content of 0.3-0.8 mmol / g.

[0014] A amino-terminated polydimethylsiloxane is bonded to a bridging agent at one end, while the other end extends freely to form a liquid-like polymer brush layer, providing an extremely low coefficient of friction; when the PDMS molecular chains break due to wear, the Ni released by ZIF... 2+ / Co 2+As a coordination catalyst, the ions first coordinate with the silicon-oxygen bonds (-Si-O-) at the broken end of the PDMS chain, activating the silicon-oxygen bonds and making them nucleophilic reaction sites. At the same time, they form metal-sulfur coordination bonds with the thiol groups (-SH) generated by the bridging agent's disulfide bond breakage, lowering the nucleophilic reaction energy barrier of the thiol groups. Ultimately, the broken end of the PDMS chain undergoes a nucleophilic addition reaction with the thiol groups to achieve rebonding. Under the catalysis of the metal ions released by ZIF, the broken chain rebonds with the newly exposed thiol groups of the bridging agent, achieving self-replenishment of the lubricating layer.

[0015] Preferably, the epoxy resin is selected from one or more of bisphenol A type epoxy resin, bisphenol F type epoxy resin, or phenolic epoxy resin; the curing agent is selected from one or more of polyether amine, modified amine, or acid anhydride curing agent; and the additives include one or more of defoamer, leveling agent, and dispersant.

[0016] The scope of this invention was determined through systematic experiments: Below the lower limit (e.g., ZIF addition < 5 parts): the improvement in abrasion resistance is not significant (preliminary experiments show abrasion amount > 20 mg / 1000r), and the purpose of this invention cannot be achieved; Exceeding the upper limit (e.g., ZIF addition > 20 parts): The coating viscosity increases sharply, the application performance decreases, and the cost increases significantly without a proportional improvement in performance; Metal ion:ligand molar ratio <1:2.5: ZIF crystallinity decreases, specific surface area <800m² 2 / g, the enhancing effect is weakened; Metal ion:ligand molar ratio > 1:3.5: high coordination saturation, insufficient unsaturated sites, and loss of catalytic function; Disulfide bond crosslinking agent dosage <5%: self-repair efficiency <70%, insufficient repair effect; When the amount of disulfide crosslinking agent is >20%, the stability of the bridging agent decreases and the shelf life is shortened.

[0017] This invention also provides a method for preparing the above-mentioned polymeric wear-resistant material, comprising the following steps: (1) Preparation of wear-resistant bimetallic organic framework with coordination unsaturated sites: Cobalt salt and nickel salt were dissolved in an organic solvent, imidazole ligands were added, and coordination reaction was carried out under ultrasonic assistance. By adjusting the molar ratio of metal ions to ligands to 1:2.5-1:3.5, coordination unsaturated metal sites were left on the surface of the obtained ZIF-67@NiCo crystal. The crystals were centrifuged at 8000-10000 r / min, washed, and dried to obtain the wear-resistant reinforcement. (2) Preparation of mussel biomimetic multifunctional interface bridging agent containing dynamic covalent bonds: In a buffer solution with pH=8.0-9.0, add dopamine hydrochloride, chitosan with a degree of deacetylation ≥95%, a crosslinking agent containing dynamic covalent bonds and a silane coupling agent, react at 20-40℃ for 12-36 hours, dialyze through a dialysis bag with a molecular weight cutoff of 3500 and freeze dry to obtain the interface bridging agent; (3) Preparation of amino-terminated polydimethylsiloxane: Hydroxyl-terminated polydimethylsiloxane with a molecular weight of 2000-5000 is reacted with aminosilane at 70-100℃ for 4-10 hours in the presence of a catalyst, and purified to obtain amino-terminated polydimethylsiloxane (NH2-PDMS-NH2) with a molecular weight of 2000-6000 and an amino content of 0.3-0.8 mmol / g. (4) Mix the wear-resistant reinforcement, interface bridging agent, epoxy resin and additives evenly to obtain component A; mix the curing agent and double-amino-terminated polydimethylsiloxane evenly to obtain component B; (5) Mix components A and B and apply them to a substrate that has been sandblasted to Sa2.5 grade and cleaned with acetone to remove oil by spraying, brushing or rolling. After curing, a polymer wear-resistant material is obtained.

[0018] Preferably, the cobalt salt in step (1) is cobalt nitrate, cobalt acetate, or cobalt chloride; the nickel salt is nickel nitrate, nickel acetate, or nickel chloride; the molar ratio of the cobalt salt to the nickel salt is 1:0.5-1:2; the imidazole ligand is 2-methylimidazole; the ultrasonic-assisted power is 200-500W, the time is 20-60 minutes, and mechanical stirring is provided during the reaction.

[0019] Preferably, the crosslinking agent containing dynamic covalent bonds in step (2) is one of 2,2'-dithiodiethylamine, 4,4'-dithiodiphenylamine, or dithiodipropionic acid; the silane coupling agent is γ-methacryloyloxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, or γ-glycidyl etheroxypropyltrimethoxysilane; and the mass ratio of dopamine hydrochloride, chitosan, the crosslinking agent containing dynamic covalent bonds, and the silane coupling agent is 1:0.3-0.8:0.1-0.4:0.3-0.8.

[0020] Preferably, the catalyst in step (3) is dibutyltin dilaurate or tetraisopropyl titanate.

[0021] Preferably, the curing conditions in step (5) are: first, pre-curing at 50-80℃ for 1-3 hours, and then post-curing at 100-140℃ for 0.5-2 hours, so that the double-ended amino-terminated polydimethylsiloxane and the interface bridging agent can fully react to form a liquid-like polymer brush layer.

[0022] When the coating is subjected to friction: Frictional heat triggers the activation of coordination unsaturated sites on the ZIF-67@NiCo surface, simultaneously inducing partial decomposition of the framework and releasing Ni. 2+ / Co 2+ Ions form a wear-resistant transfer film; When microcracks extend to the bridging agent region, dynamic disulfide bonds break preferentially due to stress concentration, exposing thiol active sites, which then re-bond with the substrate or resin matrix, achieving self-healing of the cracks. The surface PDMS molecular chains break under frictional shearing, resulting in decreased lubrication performance. The broken chains are then rebonded with newly exposed thiol groups in the bridging agent or unreacted amino groups in the coating under the catalysis of metal ions released by ZIF, thus reforming the polymer brush structure.

[0023] The three stages mentioned above are coupled with each other: the metal sites of ZIF catalyze the rebonding of PDMS and participate in the formation of the transfer film; the bond breaking of the bridging agent not only achieves interface enhancement but also provides new anchor points for PDMS; the lubricating effect of PDMS reduces frictional heat and delays the excessive decomposition of ZIF, so that the sacrificial rate of the wear-resistant reinforcement and the regeneration rate of the lubricating layer reach a dynamic balance.

[0024] Compared with the prior art, the embodiments of this application have the following main advantages: The polymeric wear-resistant material and its preparation method provided by this invention construct a closed-loop intelligent response system of friction triggering, in-situ catalysis, interface self-reinforcement, and lubrication self-replenishment through chemical matching of ZIF-67@NiCo containing coordinating unsaturated sites, mussel biomimetic bridging agent containing dynamic covalent bonds, and double-terminated amino-capped PDMS. This system breaks through the technical bottleneck of the single function of traditional wear-resistant coatings. The coating adhesion is ≥17MPa, the coefficient of friction is ≤0.12, the wear amount is ≤15mg / 1000r, the self-repair efficiency is ≥80%, and the coating life is 4-6 times that of conventional wear-resistant coatings. Moreover, the raw materials are all commercially available, the preparation process is mild, and the construction method is flexible, making it suitable for large-scale industrial production. It can be widely used in wear protection of industrial equipment in industries such as mining, cement, power, and ports, and has significant economic and social benefits. Attached Figure Description

[0025] Figure 1 This is a flowchart of a polymer wear-resistant material and its preparation method provided by the present invention.

[0026] Figure 2 This is a comparison chart of the friction coefficients of Examples 1-5 and Comparative Examples 1-6 of the present invention.

[0027] Figure 3 This is a comparison chart of wear amount in Examples 1-5 and Comparative Examples 1-6 of the present invention. Detailed Implementation

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein in the specification of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings of this application are used to distinguish different objects, not to describe a particular order.

[0029] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0030] Example 1 This invention provides a method for preparing a polymeric wear-resistant material, such as... Figure 1 As shown, it includes the following steps: (1) Preparation of ZIF-67@NiCo wear-resistant reinforcement containing coordination unsaturated sites 0.6 g of cobalt nitrate hexahydrate (0.002 mol) and 0.4 g of nickel nitrate hexahydrate (0.00136 mol) were dissolved in 50 mL of methanol, denoted as solution A. 1.0 g of 2-methylimidazole (0.0084 mol) was dissolved in 50 mL of methanol (metal ion to ligand molar ratio 1:2.5), denoted as solution B. Solution B was rapidly poured into solution A under ultrasonic power of 300 W with mechanical stirring, and the reaction was ultrasonically carried out for 30 minutes. The product was centrifuged at 8000 r / min, washed three times with methanol, and vacuum dried at 60 °C for 12 hours to obtain ZIF-67@NiCo powder. The particle size was measured to be 600-900 nm using a laser particle size analyzer. XPS and FT-IR characterization of the powder revealed a surface unsaturated site density of 0.95 sites / nm. 2 FT-IR at 1580cm -1 The appearance of a characteristic peak shift confirms the existence of coordination unsaturated sites.

[0031] (2) Preparation of mussel biomimetic multifunctional interface bridging agent containing disulfide bonds (5% disulfide bond crosslinking agent) Add 100 mL of Tris-HCl buffer (pH 8.5) to a reaction flask, then add 2 g of dopamine hydrochloride, 1 g of chitosan with a degree of deacetylation ≥ 95%, and 0.15 g of 2,2'-dithiodiethylamine (5% of the total mass of the bridging agent). After stirring to dissolve, add 1 g of KH-570 and stir at room temperature for 24 hours. Dialyze the reaction solution through a dialysis bag with a molecular weight cutoff of 3500 for 48 hours, and freeze-dry to obtain the interfacial bridging agent.

[0032] (3) Preparation of amino-terminated polydimethylsiloxane 10 g of hydroxyl-terminated polydimethylsiloxane (molecular weight 3000) was dissolved in 50 mL of toluene, and 1.5 g of γ-aminopropyltriethoxysilane and 0.1 g of dibutyltin dilaurate were added. The mixture was reacted at 80 °C under nitrogen protection for 6 hours. The solvent was removed by vacuum distillation to obtain NH2-PDMS-NH2 with an amino content of 0.52 mmol / g.

[0033] (4) Preparation of wear-resistant coating Component A: Mix 100g of epoxy resin E-51, 5g of ZIF-67@NiCo prepared in step (1), 2g of interface bridging agent prepared in step (2), and 0.5g of defoamer, and ultrasonically disperse for 30 minutes.

[0034] Component B: Mix 20g of polyetheramine D-230 and 5g of NH2-PDMS-NH2 prepared in step (3) evenly.

[0035] Mix components A and B at a mass ratio of 100:25 and apply the mixture to the surface of the sandblasted steel plate by spraying. The coating thickness is 200-250μm. Pre-cur at 60℃ for 2 hours and post-treat at 120℃ for 1 hour.

[0036] Example 2 (1) Preparation of ZIF-67@NiCo wear-resistant reinforcement: the molar ratio of metal ions to ligands is 1:2.8, and the rest is the same as in Example 1.

[0037] (2) Preparation of interfacial bridging agent: 0.24 g of 2,2'-dithiodiethylamine (8% of the total mass of the bridging agent) was used, and the rest was the same as in Example 1.

[0038] (3) Preparation of NH2-PDMS-NH2: Same as in Example 1.

[0039] (4) Preparation of wear-resistant coating Component A: 100g epoxy resin, 8g ZIF-67@NiCo, 4g interface bridging agent, 0.5g defoamer.

[0040] Component B: Polyetheramine D-230 24g, NH2-PDMS-NH2 7.5g.

[0041] Components A and B are mixed in a ratio of 100:31.5 and applied by spraying. The curing conditions are the same as in Example 1.

[0042] Example 3 (1) Preparation of ZIF-67@NiCo wear-resistant reinforcement: the molar ratio of metal ions to ligands is 1:3.0, and the rest is the same as in Example 1.

[0043] (2) Preparation of interfacial bridging agent: 0.36 g of 2,2'-dithiodiethylamine (accounting for 12% of the total mass of the bridging agent), the rest is the same as in Example 1.

[0044] (3) Preparation of NH2-PDMS-NH2: Same as in Example 1.

[0045] (4) Preparation of wear-resistant coating Component A: 100g epoxy resin, 12.5g ZIF-67@NiCo, 6g interface bridging agent, 0.5g defoamer.

[0046] Component B: Polyetheramine D-230 30g, NH2-PDMS-NH2 10g.

[0047] Components A and B are mixed in a ratio of 100:40 and applied by spraying. The curing conditions are the same as in Example 1.

[0048] Example 4 (1) Preparation of ZIF-67@NiCo wear-resistant reinforcement: the molar ratio of metal ions to ligands is 1:3.2, and the rest is the same as in Example 1.

[0049] (2) Preparation of interfacial bridging agent: 0.48 g of 2,2'-dithiodiethylamine (accounting for 16% of the total mass of the bridging agent), the rest is the same as in Example 1.

[0050] (3) Preparation of NH2-PDMS-NH2: Same as in Example 1.

[0051] (4) Preparation of wear-resistant coating Component A: 100g epoxy resin, 16g ZIF-67@NiCo, 8g interface bridging agent, 0.5g defoamer.

[0052] Component B: Polyetheramine D-230 35g, NH2-PDMS-NH2 12.5g.

[0053] Components A and B are mixed in a ratio of 100:47.5 and applied by spraying. The curing conditions are the same as in Example 1.

[0054] Example 5 (1) Preparation of ZIF-67@NiCo wear-resistant reinforcement: the molar ratio of metal ions to ligands is 1:3.5, and the rest is the same as in Example 1.

[0055] (2) Preparation of interfacial bridging agent: 0.6g of 2,2'-dithiodiethylamine (accounting for 20% of the total mass of the bridging agent), the rest is the same as in Example 1.

[0056] (3) Preparation of NH2-PDMS-NH2: Same as in Example 1.

[0057] (4) Preparation of wear-resistant coating Component A: 100g epoxy resin, 20g ZIF-67@NiCo, 10g interface bridging agent, 0.5g defoamer.

[0058] Component B: Polyetheramine D-230 40g, NH2-PDMS-NH2 15g.

[0059] Components A and B are mixed in a ratio of 100:55 and applied by spraying. The curing conditions are the same as in Example 1.

[0060] Comparative Example 1 (without ZIF-67@NiCo, conventional filler) In step (4), ZIF-67@NiCo is removed and replaced with an equal amount of nano-alumina (particle size 500nm), and the rest is the same as in Example 3.

[0061] Comparative Example 2 (no coordinating unsaturated sites) In step (1), ZIF-67@NiCo was prepared according to the conventional coordination saturation ratio: Under the same ultrasonic power, reaction temperature and stirring rate as in Example 3, the molar ratio of metal ions to ligands was adjusted to 1:4, and the remaining preparation parameters, morphology and particle size control were the same as in Example 3; the rest were the same as in Example 3.

[0062] Comparative Example 3 (without dynamic covalent bonds) In step (2), 2,2'-dithiodiethylamine was removed and replaced with a conventional KH-570 modified dopamine-chitosan coupling agent; the rest was the same as in Example 3.

[0063] Comparative Example 4 (PDMS without dual-terminated amino groups, conventional lubricant) In step (3), NH2-PDMS-NH2 is removed and replaced by adding an equal amount of conventional methyl silicone oil (without active end groups) directly to the coating. The rest is the same as in Example 3.

[0064] Comparative Example 5 (without bridging agent) Step (2) is cancelled, and no interface bridging agent is added in step (4). The rest is the same as in Example 3.

[0065] Comparative Example 6 (Commercially available wear-resistant epoxy coating) A commercially available brand of wear-resistant epoxy coating was prepared and applied according to the product instructions.

[0066] Performance testing Test method: Adhesion: The adhesion was tested according to GB / T 5210-2006 "Paints and Varnishes - Pull-off Adhesion Test" using a PosiTest AT-M pull-off adhesion tester.

[0067] Friction coefficient and wear amount: The test was conducted in accordance with GB / T 3960-2016 "Test Method for Sliding Friction and Wear of Plastics", using an M-200 friction and wear testing machine, with a load of 200N, a rotation speed of 200r / min, a grinding ring of 45# steel, and a test time of 2 hours.

[0068] Taber wear: The test was conducted according to GB / T 1768-2006 "Determination of abrasion resistance of paints and varnishes - Rotary rubber grinding wheel method". A TABER 5135 abrasion tester was used with a CS-17 grinding wheel, a load of 1000g, a rotation speed of 60 r / min, and a wear rate of 1000 revolutions.

[0069] Self-healing performance: A cross-shaped scratch was made on the coating surface with a blade, with the scratch depth controlled at 50μm (total coating thickness 200-250μm, scratch extending to the middle of the coating). After 24 hours, the changes in the scratches were observed, and the coefficient of friction in the scratched area was tested. The self-healing efficiency was calculated using the following formula: Repair efficiency (%) = [(μ0-μ r ) / (μ0-μ s )]×100% Where μ0 is the coefficient of friction of the original coating (unscratched); μ r The coefficient of friction for the repaired scratched area; μ s The measured friction coefficient between a blank Q235 steel plate substrate and 45# steel is 0.65. As shown in the table above, the polymer wear-resistant materials of Examples 1-5 of this invention all exhibit excellent comprehensive performance, with adhesion ≥17.2MPa, friction coefficient ≤0.12, Taber wear ≤14.5mg / 1000r, and self-repair efficiency ≥81.2%. Furthermore, the coating performance is gradually optimized with the gradient increase of ZIF-67@NiCo addition amount and disulfide crosslinking agent content, with Example 3 being the preferred formulation.

[0070] Compared to the comparative examples, the absence of any core innovation leads to a significant decrease in coating performance: Comparative Example 1, which uses conventional nano-alumina filler instead of ZIF-67@NiCo, shows a 247.6% increase in wear and a self-healing efficiency of only 11.8%, indicating the crucial role of ZIF-67@NiCo's "controlled sacrifice-in-situ catalysis" function in coating wear resistance and self-healing; Comparative Example 2, lacking coordination unsaturated sites, loses its catalytic function, resulting in a 144.4% increase in friction coefficient and a 60.1% decrease in self-healing efficiency; Comparative Example 3, lacking dynamic covalent bonds, cannot break the bridging agent to expose active sites, thus failing to achieve interface self-reinforcement, significantly reducing adhesion and self-healing efficiency; Comparative Example 4, retaining dynamic disulfide bonds but lacking double-terminated amino PDMS, while achieving interface crack self-healing, lacks a self-replenishing lubricating layer, and frictional shearing damages the repair interface, resulting in a self-healing efficiency lower than the examples but significantly higher than Comparative Example 3; Comparative Example 5, lacking a mussel-inspired bridging agent, experiences a sharp decrease in the adhesion between the coating and the substrate, with an adhesion of only 8.7 MPa, making the coating prone to peeling and completely losing its usability.

[0071] The Taber wear amount in Example 3 was only 8.4 mg / 1000 r, far lower than the average performance of Comparative Examples 1, 2, and 3 (24.2 mg / 1000 r). This indicates that the closed-loop intelligent response system formed by the three core innovations of this invention is not a simple functional superposition of existing technologies, but rather produces an unexpected technical effect of 1+1+1>3. Compared with commercially available wear-resistant epoxy coatings (Comparative Example 6), the friction coefficient of this invention is reduced by 78.6%, the wear amount is reduced by 83.3%, and the adhesion is improved by 48%. It achieves a synergistic improvement in wear resistance, high adhesion, self-repair, and lubrication self-replenishment, demonstrating significant technological progress. The coating life is extended to 4-6 times that of conventional coatings, and it has important industrial application value.

[0072] This invention determines the optimal range of each raw material and parameter through a series of systematic experiments. Combined with data from Examples 1-5, it can be seen that: ZIF-67@NiCo wear-resistant reinforcement: 5-20 parts. When the amount is less than 5 parts (Example 1), the improvement in wear resistance is not obvious, and the wear amount is 14.5 mg / 1000 r. When the amount is more than 20 parts, slight agglomeration is likely to occur, and the performance plateaus (Example 5). Therefore, the amount is limited to 5-20 parts. Interface bridging agent: 2-10 parts. If the amount is less than 2 parts, the adhesion is <17MPa. If the amount is more than 10 parts, the crosslinking density of the coating is too high, and the toughness decreases. The molar ratio of metal ion to ligand is 1:2.5-1:3.5. When the ratio is below 1:2.5, the crystallinity of ZIF decreases and the specific surface area is <800m². 2 / g; coordination saturation occurs above 1:3.5, with no catalytic sites (Comparative Example 2). Disulfide bond crosslinking agent dosage: 5-20%. When it is below 5%, the self-healing efficiency is <80%. When it is above 20%, the stability of the bridging agent decreases and the storage period is shortened.

[0073] It should be noted that, for the sake of simplicity, the foregoing embodiments are all described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to the present invention. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0074] It should be understood that the disclosed apparatus can be implemented in other ways, as illustrated in the embodiments provided in this application. For example, the apparatus embodiments described above are merely illustrative; the division of units described above is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or communication connections shown or discussed may be through some interfaces; the indirect coupling or communication connections between devices or units may be telecommunications or other forms.

[0075] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0076] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on these embodiments, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art can still combine, add, delete, or otherwise adjust the features of the various embodiments of the present invention according to the circumstances without conflict or creative effort, thereby obtaining different technical solutions that do not fundamentally depart from the concept of the present invention. These technical solutions also fall within the scope of protection of the present invention.

Claims

1. A polymeric wear-resistant material, characterized in that, It is prepared from the following raw materials in parts by weight: 100 parts epoxy resin; 5-20 parts of a bimetallic organic framework wear-resistant reinforcement containing coordination unsaturated sites; 2-10 parts of a mussel-inspired multifunctional interface bridging agent containing dynamic covalent bonds; 5-15 parts of amino-terminated polydimethylsiloxane; 20-40 parts of curing agent; 0-2 parts of auxiliary agent; The wear-resistant reinforcement containing coordinating unsaturated sites of the bimetallic organic framework is a ZIF-67@NiCo nanocrystal synthesized by regulating the molar ratio of metal ions to organic ligands and having residual coordinating unsaturated metal sites on its surface; the mussel-inspired multifunctional interface bridging agent containing dynamic covalent bonds is a block copolymer synthesized from dopamine, chitosan, a crosslinking agent containing dynamic covalent bonds, and a silane coupling agent; the molecular weight of the amino-terminated polydimethylsiloxane is 2000-6000.

2. The polymeric wear-resistant material as described in claim 1, characterized in that, In the bimetallic organic framework wear-resistant reinforcement containing coordination unsaturated sites, the molar ratio of metal ions to organic ligands is 1:2.5-1:3.5, and the ZIF-67@NiCo has a particle size of 300nm-1.5μm and a specific surface area ≥1000m². 2 / g.

3. The polymeric wear-resistant material as described in claim 1, characterized in that, In the mussel-inspired multifunctional interface bridging agent containing dynamic covalent bonds, the dynamic covalent bonds are selected from disulfide bonds or Schiff base bonds; the crosslinking agent containing dynamic covalent bonds is selected from 2,2'-dithiodiethylamine, 4,4'-dithiodiphenylamine or dithiodipropionic acid; the crosslinking agent containing dynamic covalent bonds accounts for 5-20% of the total mass of the bridging agent.

4. The polymeric wear-resistant material as described in claim 1, characterized in that, The amino-terminated polydimethylsiloxane has a molecular weight of 3000-5000 and an amino content of 0.3-0.8 mmol / g.

5. The polymeric wear-resistant material as described in claim 1, characterized in that, The epoxy resin is selected from one or more of bisphenol A type epoxy resin, bisphenol F type epoxy resin, or phenolic epoxy resin; the curing agent is selected from one or more of polyether amine, modified amine, or acid anhydride curing agent; the additives include one or more of defoamer, leveling agent, and dispersant.

6. A method for preparing a polymeric wear-resistant material according to any one of claims 1-5, characterized in that, Includes the following steps: (1) Preparation of wear-resistant reinforcement with bimetallic organic framework containing coordination unsaturated sites: Cobalt salt and nickel salt were dissolved in an organic solvent, imidazole ligands were added, and coordination reaction was carried out under ultrasonic assistance. By adjusting the molar ratio of metal ions to ligands to 1:2.5-1:3.5, coordination unsaturated metal sites were left on the surface of the obtained ZIF-67@NiCo crystal. After centrifugation, washing and drying, wear-resistant reinforcement was obtained. (2) Preparation of mussel biomimetic multifunctional interface bridging agent containing dynamic covalent bonds: In a buffer solution with pH=8.0-9.0, add dopamine hydrochloride, chitosan, crosslinking agent containing dynamic covalent bonds and silane coupling agent, react at 20-40℃ for 12-36 hours, and obtain the interface bridging agent by dialysis and freeze drying; (3) Preparation of amino-terminated polydimethylsiloxane: Hydroxyl-terminated polydimethylsiloxane with a molecular weight of 2000-5000 is reacted with aminosilane at 70-100℃ for 4-10 hours in the presence of a catalyst, and purified to obtain amino-terminated polydimethylsiloxane with a molecular weight of 2000-6000 and an amino content of 0.3-0.8 mmol / g; (4) Mix the wear-resistant reinforcement, interface bridging agent, epoxy resin and additives evenly to obtain component A; mix the curing agent and double-amino-terminated polydimethylsiloxane evenly to obtain component B; (5) Mix components A and B, coat them onto a substrate that has been sandblasted to Sa2.5 grade and cleaned with acetone to remove oil, and cure to obtain a polymer wear-resistant material.

7. The method for preparing the polymeric wear-resistant material as described in claim 6, characterized in that, The cobalt salt in step (1) is cobalt nitrate, cobalt acetate, or cobalt chloride; the nickel salt is nickel nitrate, nickel acetate, or nickel chloride; the molar ratio of the cobalt salt to the nickel salt is 1:0.5-1:2; the imidazole ligand is 2-methylimidazole; the ultrasonic-assisted power is 200-500W, the time is 20-60 minutes, and mechanical stirring is provided during the reaction.

8. The method for preparing the polymeric wear-resistant material as described in claim 6, characterized in that, The crosslinking agent containing dynamic covalent bonds mentioned in step (2) is one of 2,2'-dithiodiethylamine, 4,4'-dithiodiphenylamine, or dithiodipropionic acid; the silane coupling agent is γ-methacryloyloxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, or γ-glycidoxypropyltrimethoxysilane; the mass ratio of dopamine hydrochloride, chitosan, the crosslinking agent containing dynamic covalent bonds, and the silane coupling agent is 1:0.3-0.8:0.1-0.4:0.3-0.

8.

9. The method for preparing the polymeric wear-resistant material as described in claim 6, characterized in that, The catalyst mentioned in step (3) is dibutyltin dilaurate or tetraisopropyl titanate.

10. The method for preparing the polymeric wear-resistant material as described in claim 6, characterized in that, The curing conditions described in step (5) are as follows: first, pre-curing at 50-80℃ for 1-3 hours, and then post-curing at 100-140℃ for 0.5-2 hours, so that the double-terminated amino-terminated polydimethylsiloxane and the interface bridging agent can fully react to form a liquid-like polymer brush layer.

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