Highly adhesive composite material for rubber dams and method for its production

Abstract

The present application relates to a kind of high adhesive composite material for rubber dam and its preparation method, it is related to rubber dam technical field, wherein the high adhesive composite material for rubber dam includes the weatherproof layer of outer layer, the reinforcing layer of middle, inner layer self-repairing layer, by mass fraction, the weatherproof layer includes 90-110 parts high saturated nitrile rubber, 23-28 parts carbon black N550, 3-8 parts nano TiO2, 1-3 parts antioxidant 1010, 2-3 parts of dicumyl peroxide, the reinforcing layer includes 60-80 parts of ethylene-propylene-diene rubber, 25-35 parts of butadiene-styrene rubber, 13-15 parts, nylon fiber, 10-12 parts aramid fiber, 12-15 parts carbon black, 0.5-1.5 parts graphene, 1-2 parts of sulfur, 0.5-1.5 parts of accelerator CZ, the self-repairing layer includes 90-100 parts of silicone rubber, 5-10 parts nano SiO2, 5-8 parts self-repairing agent, 0.1-0.3 parts dispersant.The high adhesive composite material for rubber dam of the present application has good adhesion, can repair small crack in time, prevent the further expansion of crack.

Description

Technical Field

[0001] This invention relates to the field of rubber dam technology, and in particular to a highly adhesive composite material for rubber dams, its preparation method, and its application. Background Technology

[0002] Rubber dams, as an important hydraulic engineering structure, are widely used in various fields such as water flow regulation, flood control, irrigation, and power generation. Due to their numerous advantages, including novel design, aesthetic appeal, simple construction, convenient management, short construction period, low investment, and quick results, they have been widely applied and rapidly developed in various hydraulic engineering fields such as water conservancy, hydropower, water transport, moisture control, and environmental beautification. Compared with traditional earth, rock, steel, and wood dams, rubber dams have advantages such as lower cost, savings in materials, shorter construction period, better seismic performance, and better water-stopping effect.

[0003] Chinese invention patent application CN112252276A discloses a movable water-filled rubber dam. The rubber dam includes a high-strength fiber skeleton, a vulcanized rubber layer, a water inlet, a drainage outlet, and an anchoring mechanism. The dam bag is generally similar to an inverted trapezoid, with a high-strength fiber skeleton inside. The surface of the high-strength fiber skeleton is covered with multiple layers of vulcanized rubber. A water injection device is provided at the top of the rubber dam, and the water inlet is connected to the external water injection mechanism. A drainage device is provided at the bottom of the rubber dam, and anchoring mechanisms are provided on both sides of the rubber dam for anchoring or connection.

[0004] This invention proposes a portable, water-filled rubber dam with a simple and practical structure. Its internal high-strength fiber skeleton is wear-resistant and durable. Its unique structure not only blocks water but also allows for vehicle passage. However, when exposed to the external environment for extended periods, ultraviolet radiation causes the rubber molecular chains to break, leading to photo-oxidation and surface cracking of the rubber layer, resulting in microcracks. These microcracks expand over time. Ozone in the environment readily reacts with double bonds in the rubber, triggering the expansion of microcracks. Pollutants in the water (such as oils, acids, alkalis, and chloride ions) can penetrate the rubber, damaging the cross-linked structure and reducing toughness. Initially, microcracks easily appear, but as pollutants accumulate, these microcracks expand into larger ones. Diurnal or seasonal temperature differences cause thermal expansion and contraction of the rubber dam material, and repeated deformation can also lead to cracking. In cold environments, the rubber's elasticity decreases, and its brittleness increases, making it prone to microcracks at weak points when filled with water. In summary, there are many reasons why microcracks appear in rubber dams. External stress or aging can both lead to the formation of microcracks, and it is difficult to completely avoid them. As time goes on, microcracks will further expand. Therefore, it is particularly important for rubber dams to have self-repair capabilities when microcracks appear. Summary of the Invention

[0005] To solve the above technical problems, the present application provides a high-adhesion composite material for rubber dam and a preparation method thereof. The high-adhesion composite material for rubber dam has good adhesion and can timely repair small cracks and prevent further expansion of cracks.

[0006] In the first aspect, the present application provides a high-adhesion composite material for rubber dam, which comprises an outer weather-resistant protective layer, an intermediate reinforcing layer, and an inner self-repairing layer. The weather-resistant protective layer comprises, by mass fraction, 90-110 parts of high-saturation nitrile rubber, 23-28 parts of carbon black N550, 3-8 parts of nano-TiO2, 1-3 parts of antioxidant 10101, and 2-3 parts of dicumyl peroxide. The reinforcing layer comprises, by mass fraction, 60-80 parts of ethylene-propylene-diene rubber, 25-35 parts of styrene-butadiene rubber, 13-15 parts of nylon fiber, 10-12 parts of aramid fiber, 12-15 parts of carbon black, 0.5-1.5 parts of graphene, 1-2 parts of sulfur, and 0.5-1.5 parts of accelerator CZ. The self-repairing layer comprises, by mass fraction, 90-100 parts of silicone rubber, 5-10 parts of nano-SiO2, 5-8 parts of self-repairing agent, and 0.1-0.3 parts of dispersant.

[0007] In the above technical solution, the double bond content of high-saturation nitrile rubber in the weather-resistant protective layer is extremely low, significantly reducing the oxidative degradation induced by ozone and ultraviolet light. Dicumyl peroxide can decompose to generate free radicals at high temperatures, initiating cross-linking reactions between the molecular chains of high-saturation nitrile rubber, forming a three-dimensional network structure, and improving the tensile strength, elastic modulus, and deformation resistance of the material. Carbon black particles absorb and scatter ultraviolet light, reducing photo-oxidation reactions and delaying rubber aging. Nano-TiO2 decomposes surface organic matter (such as algae) through photocatalysis and reflects ultraviolet light, reducing photo-degradation.

[0008] In the reinforcing layer, ethylene-propylene-diene rubber has strong aging resistance, and aramid fiber has high tensile strength, bearing the main tensile stress and preventing excessive deformation of the dam body. Nylon fiber can absorb impact energy and delay crack propagation through plastic deformation, forming a reinforcing network with aramid fiber. Graphene can form a three-dimensional network in the ethylene-propylene-diene rubber and styrene-butadiene rubber matrix, hindering crack propagation through the "crack pinning effect" and improving tear resistance, while also improving thermal conductivity to avoid local overheating.

[0009] In the self-repairing layer, silicone rubber as the main body of the self-repairing layer can provide high elasticity and flexibility to meet the deformation requirements of the dam. Nano-SiO2 particles are dispersed in the silicone rubber matrix, inhibiting molecular chain embrittlement at low temperatures through physical cross-linking points, improving the elasticity of the material under low temperature conditions, increasing the hardness and wear resistance of the rubber matrix, and cooperating with the self-repairing agent to delay the crack propagation path and gain time for self-repair.

[0010] Optionally, the self-repairing agent is a microcapsule self-repairing agent, the microcapsule self-repairing agent includes 30-32% of core material, 68-70% of shell material, and 0.2-0.3% of emulsifier by mass percentage, the core material includes liquid polysulfide rubber, nano ZnO, and silane coupling agent, the mass ratio of the liquid polysulfide rubber, the nano ZnO, and the silane coupling agent is 8-10:1:0.1-0.2, and the shell material includes urea, formaldehyde, ammonium chloride, and water, the mass ratio of the urea, the formaldehyde, the ammonium chloride, and the water is 1:1.2-1.5:0.05-0.1:9-10.

[0011] In the above technical solution, the crack tip stress triggers the microcapsule to break during the crack propagation process, and the liquid polysulfide rubber and the nano ZnO modified by the silane coupling agent are released, the modified nano ZnO acts as a crosslinking catalyst, reacts with the liquid polysulfide rubber to generate a polysulfide network (-S-S- bond), and quickly fills the microcracks.

[0012] Optionally, the nylon fiber is a modified nylon fiber, and the preparation steps of the modified nylon fiber are as follows: 5% of silane coupling agent is mixed with 95% of ethanol, 1% of acetic acid is added to adjust the pH to 4-5, the nylon fiber is immersed in the treatment solution, constant temperature stirring is performed at 50-70°C for 1-3h, drying is performed at 75-85°C for 1-2h, then vacuum is drawn to 10 -2 Pa, oxygen is introduced, under the conditions of a power of 45-55W and a gas flow of 18-22sccm, the surface of the nylon fiber is bombarded by plasma for 3-7min, and the modified nylon fiber is obtained.

[0013] In the above technical solution, the nylon fiber is treated by the silane coupling agent and the plasma, the surface polar groups (-NH2, -OH) form chemical bonding with the rubber matrix, interlayer peeling is prevented, the chemical bonding with the rubber is improved, and the adhesion of the composite material is improved.

[0014] Optionally, the silicone rubber is a modified silicone rubber, and the preparation steps of the modified silicone rubber are as follows: methyl vinyl silicone rubber and 3-aminopropyl trimethoxysilane are added to toluene and reacted at 75-85°C for 5-7h, the mass ratio of the methyl vinyl silicone rubber and the 3-aminopropyl trimethoxysilane is 18-22:1, then bismaleimide is added and mixed according to a mass ratio of 10-12:1, stirring is performed for 3-7min until complete dissolution, and the mixture is placed in a drying oven at 55-60°C for 1-2h, and the modified silicone rubber is obtained.

[0015] In the above technical solution, 3-aminopropyltrimethoxysilane is hydrolyzed to form a -Si-O- bond, a furan group is introduced into the silicone rubber network, and a di-maleimide (dienophile) and a furan group (dienophile) in the silicone rubber slowly undergo a diene addition reaction at room temperature to form a reversible cross-linking bond. When the temperature is higher than 60℃, the reversible cross-linking bond dissociates, the material softens, the crack interface molecules rearrange, and after cooling, the reversible cross-linking bond reorganizes to restore the cross-linking network and close the crack.

[0016] In a second aspect, the application provides a preparation method of a high-adhesion composite material for a rubber dam, the preparation method comprising the following steps:

[0017] Preparation of the weather-resistant protective layer: high-saturation nitrile rubber is plasticized at 75-85℃ for 1-3min, carbon black, nano-TiO2, and antioxidant 1010 are sequentially added, and mixing is performed at 55-65rpm for 8-12min, then dicumyl peroxide is added, and mixing is continued for 3-7min, and the sheet is discharged and cooled;

[0018] Preparation of the reinforcing layer: EPDM rubber and SBR are plasticized at 65-70℃ for 1-5min, carbon black and graphene are added under the condition of 45-55rpm mixing for 8-12min, nylon fibers and aramid fibers with a length of 6-8mm are added, and mixing is performed for 3-7min, then sulfur and accelerator CZ are added, and mixing is performed for 3-7min before discharging;

[0019] Preparation of the self-repairing layer: silicone rubber is thin-passed 2-3 times at 20-30℃, nano-SiO2 is added and uniformly mixed, and stirring is performed at 100-150rpm, and finally self-repairing agent and dispersing agent are added, and slow rolling is performed for 3-5min to ensure uniform dispersion;

[0020] Vacuum hot-pressing vulcanization: the rubber materials of each layer are sequentially placed in a mold, water-based polyurethane adhesive is sprayed between the layers, pre-drying is performed at 75-85℃ for 3-7min, pre-pressing is performed at 4-6MPa to exhaust air, the self-repairing layer is vulcanized by first increasing the temperature to 60℃, the reinforcing layer is vulcanized by increasing the temperature to 150℃, and finally the weather-resistant protective layer is vulcanized by decreasing the temperature to 130℃, and the mold is demolded after cooling to 50℃, thereby obtaining a high-adhesion composite material.

[0021] In the above technical solution, bubbles are prone to become crack sources, and vacuum can assist in removing interlayer bubbles to prevent weak bonding at the interface. The -NCO groups in the molecular chain of the water-based polyurethane adhesive react with the -OH and -NH2 on the surface of the rubber to form chemical bonds.

[0022] Optionally, the preparation method further comprises a preparation step of microcapsule self-repairing agent, and the preparation step of the microcapsule self-repairing agent is as follows:

[0023] Preparation of core material: mix nano-ZnO with silane coupling agent, add into anhydrous ethanol, ultrasonic dispersion at 35-45 kHz for 25-35 min, stirring at 55-65℃ for 1-3 h, centrifugal at 3500-4500 rpm for 8-12 min, ethanol washing for 2-3 times, vacuum drying at 55-65℃ to obtain modified ZnO, mix modified ZnO with liquid polysulfide rubber, magnetic stirring at 45-55℃ and 450-550 rpm for 0.5-1.5 h to form a uniform suspension;

[0024] Preparation of matrix material: add urea and formaldehyde into water and stir, adjust pH to 8.0-8.5, react at 65-75℃ for 0.5-1.5 h to generate transparent urea-formaldehyde prepolymer, and then reduce to room temperature;

[0025] In-situ polymerization of microcapsules: add the suspension into the urea-formaldehyde prepolymer solution, add emulsifier, emulsify at 10000-11000 rpm for 8-12 min to form an emulsion, add ammonium chloride to the emulsion, adjust pH to 3.0-3.5, constant temperature stirring at 250-350 rpm and 50-60℃ for 2-4 h, centrifugal at 2500-3500 rpm for 3-7 min, wash the precipitate with deionized water for 2-3 times, vacuum drying at 35-45℃ for 22-26 h to obtain the microcapsule self-repairing agent.

[0026] In the above technical solution, the silane coupling agent is hydrolyzed to generate silanol (-Si(OH)3) in ethanol, the silanol condenses with the hydroxyl group (-OH) on the surface of ZnO to form Si-O-Zn covalent bond, and at the same time, amino group (-NH2) is introduced on the surface of ZnO, which improves the compatibility of ZnO and polysulfide rubber (containing -SH), prevents nanoparticle agglomeration, and ensures the homogeneous dispersion of the core material. The amino group on the surface of the ZnO modified by the silane coupling agent is combined with the thiol group (-SH) of the liquid polysulfide rubber through hydrogen bond to form a stable complex. In the self-repairing process, the modified ZnO acts as a crosslinking catalyst to react with the liquid polysulfide rubber to generate a polysulfide network (-S-S- bond), achieving rapid repair.

[0027] Urea and formaldehyde first generate intermediate such as monomethylol urea and dimethylol urea, and under alkaline conditions, the monomethylol urea further condenses to generate water-soluble low molecular weight linear urea-formaldehyde resin prepolymer.

[0028] The emulsifier such as sodium dodecyl sulfate, as an anionic surfactant, is adsorbed on the interface between the oil phase (liquid polysulfide rubber / modified ZnO) and the water phase to reduce the interfacial tension, and the sulfonic acid group (-SO3 - ) of the sodium dodecyl sulfate makes the surface of the emulsion droplets negatively charged, preventing droplet coalescence through electrostatic repulsion. High-speed shearing at 10000 rpm breaks the oil phase into small droplets. Ammonium chloride is hydrolyzed to generate H +, reduce the pH, activate the condensation reaction of methylol urea, cross-link the linear prepolymer into a three-dimensional network structure, gradually deposit on the surface of the core material droplets, and form a dense wall material.

[0029] In a third aspect, the application provides a rubber dam using the high-adhesion composite material for rubber dam or the high-adhesion composite material prepared by the preparation method of the high-adhesion composite material for rubber dam.

[0030] In a fourth aspect, the application provides the application of a rubber dam in the river regulation industry, the agricultural irrigation industry, the flood control industry, the shipping and transportation industry, and the construction of a rubber dam in a high water pressure environment.

[0031] In summary, the application has at least one of the following beneficial technical effects:

[0032] 1. In the weatherproof layer, the double bond content of the high-saturation nitrile rubber is very low, which significantly reduces the oxidative degradation caused by ozone and ultraviolet light. Carbon black particles absorb and scatter ultraviolet light, reducing photo-oxidation reactions and delaying rubber aging. Nano-TiO2 decomposes surface organic matter (such as algae) through photocatalysis, reflects ultraviolet light, and reduces photodegradation.

[0033] 2. In the reinforcement layer, the ethylene-propylene-diene rubber has strong aging resistance, and the aramid fiber has high tensile strength, which can withstand the main tensile stress and prevent the dam body from deforming excessively. The modified nylon fiber can absorb impact energy and delay crack propagation through plastic deformation, forming a reinforcing network with aramid fiber. Graphene can form a three-dimensional network in the ethylene-propylene-diene rubber and styrene-butadiene rubber matrix, hindering crack propagation through "crack pinning effect", improving tear resistance, and improving thermal conductivity to avoid local overheating.

[0034] 3. In the self-repairing layer, modified silicone rubber as the main body of the self-repairing layer can provide high elasticity and flexibility to meet the deformation requirements of the dam. Nano-SiO2 particles dispersed in the modified silicone rubber matrix inhibit molecular chain embrittlement at low temperatures through physical cross-linking points, improve the elasticity of the material at low temperatures, increase the hardness and wear resistance of the rubber matrix, and cooperate with the microcapsule self-repairing agent to delay the crack propagation path and gain time for self-repair. DETAILED DESCRIPTION

[0035] The application will be further described in detail below in conjunction with the examples.

[0036] The materials used in the following examples can be obtained by market purchase.

[0037] Example 1: This example discloses a high-adhesion composite material for rubber dam #1 and a preparation method thereof.

[0038] The high-adhesion composite material for rubber dam comprises an outer weather-resistant protective layer, an intermediate reinforcing layer and an inner self-repairing layer. The weather-resistant protective layer comprises, by mass percentage, 90 parts of high-saturation nitrile rubber, 23 parts of carbon black N550, 3 parts of nano-TiO2, 2 parts of antioxidant 1010 and 2 parts of dicumyl peroxide. The reinforcing layer comprises 60 parts of ethylene-propylene-diene rubber, 25 parts of styrene-butadiene rubber, 13 parts of nylon fiber, 12 parts of aramid fiber, 15 parts of carbon black, 0.5 part of graphene, 1 part of sulfur and 0.5 part of accelerator CZ. The self-repairing layer comprises 90 parts of silicone rubber, 5 parts of nano-SiO2, 5 parts of self-repairing agent and 0.1 part of dispersant.

[0039] The self-repairing agent comprises, by mass ratio, 100 parts of epoxidized natural rubber, 5 parts of ZnO, 1 part of stearic acid and 1.6 parts of sulfur. The dispersant in this embodiment is polyethylene glycol, and in other embodiments, the dispersant can also be polyvinylpyrrolidone, sorbitol monooleate and the like. The silicone rubber is methyl vinyl silicone rubber.

[0040] The preparation method comprises the following steps:

[0041] S1. Preparation of the weather-resistant protective layer: high-saturation nitrile rubber is plasticated at 80℃ for 2 minutes, and then carbon black, nano-TiO2 and antioxidant 1010 are added in sequence, mixed at 60 rpm for 10 minutes, dicumyl peroxide is further added and mixed for 5 minutes, and then sheeting is performed and cooled.

[0042] S2. Preparation of the reinforcing layer: ethylene-propylene-diene rubber and styrene-butadiene rubber are plasticated at 68℃ for 3 minutes, carbon black and graphene are added and mixed at 50 rpm for 10 minutes, nylon fiber and aramid fiber with a length of 6-8 mm are added and mixed for 5 minutes, and then sulfur and accelerator CZ are added and mixed for 5 minutes before discharging.

[0043] S3. Preparation of the self-repairing layer: silicone rubber is thin-passed at 25℃ for 3 times, nano-SiO2 is added and uniformly mixed, and then self-repairing agent and dispersant are added and slowly mixed for 2 minutes to ensure uniform dispersion.

[0044] S4. Vacuum hot-pressing vulcanization: the rubber materials of the layers are sequentially placed in a mold, water-based polyurethane adhesive is sprayed between the layers, pre-drying is performed at 80℃ for 5 minutes, pre-pressing is performed at 5 MPa for exhaust, the temperature is first increased to 60℃ for self-repairing layer vulcanization, then increased to 150℃ for reinforcing layer vulcanization, and finally decreased to 130℃ for weather-resistant protective layer vulcanization, pressure cooling is performed to 50℃ for demolding, and a high-adhesion composite material #1 is obtained.

[0045] Embodiment 2: The embodiment discloses a high-adhesion composite material #2 for rubber dam and a preparation method thereof.

[0046] The high-adhesion composite material for rubber dam includes an outer weather-proof layer, a middle reinforcing layer, and an inner self-repairing layer. The weather-proof layer includes, by mass percentage, 110 parts of high-saturation nitrile rubber, 28 parts of carbon black N550, 8 parts of nano-TiO2, 3 parts of antioxidant 1010, and 3 parts of dicumyl peroxide. The reinforcing layer includes 80 parts of ethylene-propylene-diene rubber, 35 parts of styrene-butadiene rubber, 14 parts of nylon fiber, 11 parts of aramid fiber, 15 parts of carbon black, 1.5 parts of graphene, 2 parts of sulfur, and 1.5 parts of accelerator CZ. The self-repairing layer includes 95 parts of silicone rubber, 6 parts of nano-SiO2, 7 parts of self-repairing agent, and 0.3 parts of polyethylene glycol. The rest is the same as in Example 1.

[0047] The method for preparing the high-adhesion composite material #2 for rubber dam is the same as in Example 1.

[0048] Example 3: This example discloses a high-adhesion composite material #3 for rubber dam and a method for preparing the same.

[0049] The high-adhesion composite material for rubber dam includes an outer weather-proof layer, a middle reinforcing layer, and an inner self-repairing layer. The weather-proof layer includes, by mass percentage, 100 parts of high-saturation nitrile rubber, 25 parts of carbon black N550, 5 parts of nano-TiO2, 2 parts of antioxidant 1010, and 2.5 parts of dicumyl peroxide. The reinforcing layer includes 70 parts of ethylene-propylene-diene rubber, 30 parts of styrene-butadiene rubber, 15 parts of nylon fiber, 10 parts of aramid fiber, 15 parts of carbon black, 1 part of graphene, 1.5 parts of sulfur, and 1 part of accelerator CZ. The self-repairing layer includes 100 parts of silicone rubber, 8 parts of nano-SiO2, 8 parts of self-repairing agent, and 0.2 parts of polyethylene glycol. The rest is the same as in Example 1.

[0050] The method for preparing the high-adhesion composite material #3 for rubber dam is the same as in Example 1.

[0051] Example 4: This example discloses a high-adhesion composite material #4 for rubber dam and a method for preparing the same.

[0052] The high-adhesion composite material for rubber dam includes an outer weather-proof layer, a middle reinforcing layer, and an inner self-repairing layer. The weather-proof layer includes, by mass percentage, 100 parts of high-saturation nitrile rubber, 25 parts of carbon black N550, 5 parts of nano-TiO2, 2 parts of antioxidant 1010, and 2.5 parts of dicumyl peroxide. The reinforcing layer includes 70 parts of ethylene-propylene-diene rubber, 30 parts of styrene-butadiene rubber, 15 parts of nylon fiber, 10 parts of aramid fiber, 15 parts of carbon black, 1 part of graphene, 1.5 parts of sulfur, and 1 part of accelerator CZ. The self-repairing layer includes 100 parts of silicone rubber, 8 parts of nano-SiO2, 8 parts of self-repairing agent, and 0.2 parts of polyethylene glycol.

[0053] The microcapsule self-repairing agent comprises 31.5% of core material, 68.25% of shell material and 0.25% of sodium dodecyl sulfate by mass percentage, the core material comprises liquid polysulfide rubber, nano ZnO and KH-550 coupling agent, the mass ratio of the liquid polysulfide rubber, nano ZnO and KH-550 coupling agent is 10:1:0.2, and the shell material comprises 10 g of urea, 15 g of formaldehyde, 0.5 g of ammonium chloride and 100 mL of water, and the mass ratio of the urea, formaldehyde, ammonium chloride and water is 1:1.5:0.05:10.

[0054] In this embodiment, the emulsifier is sodium dodecyl sulfate, and in other embodiments, other emulsifiers can also be selected. The silane coupling agent is KH-550 coupling agent, and in other embodiments, other silane coupling agents such as KH-560 can also be selected.

[0055] The preparation method comprises the following steps:

[0056] S1, preparation of the weather-resistant protective layer: high-saturation nitrile rubber is plasticated at 80℃ for 2 min, carbon black, nano TiO2 and antioxidant 1010 are sequentially added, mixing is carried out at 60 rpm for 10 min, dicumyl peroxide is further added, and mixing is continued for 5 min, and the sheet is discharged and cooled.

[0057] S2, preparation of the reinforcing layer: ethylene-propylene-diene rubber and styrene butadiene rubber are plasticated at 68℃ for 3 min, carbon black and graphene are added under the condition of 50 rpm and mixed for 10 min, nylon fibers and aramid fibers with a length of 6-8 mm are added and mixed for 5 min, sulfur and accelerator CZ are further added, and mixing is carried out for 5 min before discharging.

[0058] S3, preparation of the microcapsule self-repairing agent:

[0059] S31, preparation of the core material: nano ZnO and silane coupling agent are mixed and added into anhydrous ethanol, ultrasonic dispersion is carried out at 40 kHz for 30 min, stirring is carried out at 60℃ for 2 h, centrifugation is carried out at 4000 rpm for 10 min, ethanol washing is carried out for 3 times, and vacuum drying is carried out at 60℃ to obtain modified ZnO, the modified ZnO and liquid polysulfide rubber are mixed, magnetic stirring is carried out at 50℃ and 500 rpm for 1 h to form a uniform suspension;

[0060] S32, preparation of the shell material: urea and formaldehyde are added into water and stirred, the pH is adjusted to 8.0-8.5, and transparent urea-formaldehyde prepolymer is generated by reacting at 70℃ for 1 h, and the temperature is reduced to room temperature;

[0061] S33, in-situ polymerization of microcapsules: add the suspension to the urea-formaldehyde prepolymer solution, add an emulsifier, emulsify at 10,000 rpm for 10 min to form an emulsion, add ammonium chloride to the emulsion, adjust the pH to 3.0-3.5, stir at 300 rpm and 55°C for 3 h, centrifuge at 3,000 rpm for 5 min, wash the precipitate with deionized water 3 times, and vacuum dry at 40°C for 24 h to obtain the microcapsule self-repairing agent.

[0062] S4, preparation of the self-repairing layer: pass the silicone rubber through 3 times at 25°C, mix the nano-SiO2, stir at 150 rpm, finally add the microcapsule self-repairing agent and the dispersing agent, and slowly roll for 2 min to ensure uniform dispersion.

[0063] S5, vacuum hot pressing vulcanization: place the rubber compounds in the mold in order, spray waterborne polyurethane adhesive between the layers, pre-dry at 80°C for 5 min, pre-press at 5 MPa to exhaust, first heat to 60°C to vulcanize the self-repairing layer, then heat to 150°C to vulcanize the reinforcing layer, finally heat to 130°C to vulcanize the weather-resistant protective layer, keep pressure and cool to 50°C to demold, to obtain the high-adhesion composite material #4.

[0064] Example 5: This example discloses a high-adhesion composite material #5 for rubber dams and a preparation method thereof.

[0065] The nylon fiber in this example is a modified nylon fiber. The rest is the same as in Example 3.

[0066] The preparation method comprises the following steps:

[0067] S1, preparation of the weather-resistant protective layer: plasticize the high-saturation nitrile rubber at 80°C for 2 min, add carbon black, nano-TiO2, and antioxidant 1010 in order, mix at 60 rpm for 10 min, then add dicumyl peroxide and continue mixing for 5 min, and sheet out and cool.

[0068] S2, preparation of the modified nylon fiber: mix 5% silane coupling agent with 95% ethanol, add 1% acetic acid to adjust the pH to 4-5, immerse the nylon fiber in the treatment solution, stir at 60°C for 2 h, dry at 80°C for 1.5 h, then vacuum to 10 -2 Pa, then introduce oxygen, and plasma bombard the surface of the nylon fiber at a power of 50 W and a gas flow of 20 sccm for 5 min to obtain the modified nylon fiber.

[0069] S3, preparation of the reinforcing layer: plasticize the ethylene-propylene-diene rubber and styrene-butadiene rubber at 68°C for 3 min, add carbon black and graphene at 50 rpm and mix for 10 min, add modified nylon fiber and aramid fiber with a length of 6-8 mm and mix for 5 min, then add sulfur and accelerator CZ and mix for 5 min before discharging.

[0070] S4, Preparation of self-repairing layer: Silicon rubber was passed through three times at 25°C, nano-SiO2 was added and mixed, and stirring was performed at 150 rpm. Finally, self-repairing agent and dispersing agent were added, and slow rolling was performed for 2 min to ensure uniform dispersion.

[0071] S5, Vacuum hot pressing vulcanization: The rubber material of each layer was sequentially placed in the mold, water-based polyurethane adhesive was sprayed between the layers, 80°C pre-drying for 5 min, pre-pressing 5 MPa exhaust, first heating to 60°C vulcanization self-repairing layer, then heating to 150°C vulcanization of the reinforcing layer, and finally cooling to 130°C vulcanization of the weather-resistant protective layer, pressure cooling to 50°C demolding, to obtain high-adhesion composite material #5.

[0072] Example 6: The present embodiment discloses a high-adhesion composite material #6 for rubber dam and a preparation method thereof.

[0073] The nylon fiber in the present embodiment is a modified nylon fiber. The rest is the same as example 4.

[0074] The preparation method comprises the following steps:

[0075] S1, Preparation of weather-resistant protective layer: High-saturation nitrile rubber was plasticized at 80°C for 2 min, carbon black, nano-TiO2 and antioxidant 1010 were added in sequence, mixing was performed at 60 rpm for 10 min, dicumyl peroxide was further added, and mixing was continued for 5 min, and the sheet was cooled.

[0076] S2, Preparation of modified nylon fiber: 5% silane coupling agent was mixed with 95% ethanol, 1% acetic acid was added to adjust the pH to 4-5, the nylon fiber was immersed in the treatment solution, constant temperature stirring was performed at 60°C for 2 h, drying was performed at 80°C for 1.5 h, then vacuum was applied to 10 -2 Pa, oxygen was introduced, and the surface of the nylon fiber was bombarded by plasma for 5 min under the conditions of power 50W and gas flow 20sccm, to obtain the modified nylon fiber.

[0077] S3, Preparation of reinforcing layer: Ternary ethylene-propylene rubber and styrene-butadiene rubber were plasticized at 68°C for 3 min, carbon black and graphene were added under the condition of 50 rpm and mixing was performed for 10 min, modified nylon fiber and aramid fiber with a length of 6-8 mm were added, mixing was performed for 5 min, and sulfur and accelerator CZ were added, mixing was performed for 5 min, and then the material was discharged.

[0078] S4, Preparation of microcapsule self-repairing agent:

[0079] S41, Preparation of core material: mix nano-ZnO with silane coupling agent, add anhydrous ethanol, ultrasonic dispersion for 30 min at 40 kHz, stir for 2 h at 60 DEG C, centrifugal for 10 min at 4000 rpm, wash with ethanol for 3 times, vacuum drying at 60 DEG C to obtain modified ZnO, mix modified ZnO with liquid polysulfide rubber, magnetic stirring for 1 h at 50 DEG C and 500 rpm to form a uniform suspension;

[0080] S42, Preparation of wall material: add urea and formaldehyde to water and stir, adjust pH to 8.0-8.5, react for 1 h at 70 DEG C to generate transparent urea-formaldehyde prepolymer, and cool to room temperature;

[0081] S43, In-situ polymerization of microcapsules: add the suspension to the urea-formaldehyde prepolymer solution, add an emulsifier, emulsify for 10 min at 10000 rpm to form an emulsion, add ammonium chloride to the emulsion, adjust pH to 3.0-3.5, stir at 300 rpm and 55 DEG C for 3 h, centrifugal for 5 min at 3000 rpm, wash the precipitate with deionized water for 3 times, and vacuum drying at 40 DEG C for 24 h to obtain the microcapsule self-repairing agent.

[0082] S5, Preparation of self-repairing layer: pass the silicone rubber through 3 times at 25 DEG C, mix with nano-SiO2, and finally add the microcapsule self-repairing agent and a dispersing agent, and slowly mix for 2 min to ensure uniform dispersion.

[0083] S6, Vacuum hot pressing vulcanization: place the rubber materials in the mold in sequence, spray waterborne polyurethane adhesive between the layers, pre-dry at 80 DEG C for 5 min, pre-press at 5 MPa to exhaust, first heat to 60 DEG C to vulcanize the self-repairing layer, then heat to 150 DEG C to vulcanize the reinforcing layer, and finally cool to 130 DEG C to vulcanize the weather-resistant protective layer, and cool to 50 DEG C to demold to obtain the high-adhesion composite material #6.

[0084] Example 7 discloses a high-adhesion composite material #7 for rubber dam and a preparation method thereof.

[0085] The silicone rubber of the example is a modified silicone rubber, and the rest is the same as example 3.

[0086] The preparation method comprises the following steps:

[0087] S1, Preparation of weather-resistant protective layer: plasticize the high-saturation nitrile rubber at 80 DEG C for 2 min, add carbon black, nano-TiO2 and antioxidant 1010 in sequence, mix for 10 min at 60 rpm, then add dicumyl peroxide and continue to mix for 5 min, and sheet out and cool.

[0088] S2, Preparation of the reinforcing layer: The ethylene propylene diene rubber and styrene butadiene rubber were plasticated at 68°C for 3 min, carbon black and graphene were added and mixed at 50 rpm for 10 min, nylon fibers and aramid fibers with a length of 6-8 mm were added and mixed for 5 min, sulfur and accelerator CZ were added and mixed for 5 min before discharging.

[0089] S3, Preparation of the modified silicone rubber: Methyl vinyl silicone rubber and 3-aminopropyltrimethoxysilane were added to toluene and reacted at 80°C for 6 h, the mass ratio of the methyl vinyl silicone rubber to 3-aminopropyltrimethoxysilane was 20:1, then bismaleimide was added and mixed at a mass ratio of 10:1, stirred for 5 min until completely dissolved, and placed in a 60°C oven to dry for 1.5 h to obtain the modified silicone rubber.

[0090] S4, Preparation of the self-repairing layer: The modified silicone rubber was passed through a thin pass three times at 25°C, mixed with nano-SiO2, and stirred uniformly at 150 rpm, and finally self-repairing agent and dispersing agent were added and slowly mixed for 2 min to ensure uniform dispersion.

[0091] S5, Vacuum hot pressing vulcanization: The rubber materials of each layer were sequentially placed in the mold, water-based polyurethane adhesive was sprayed between the layers, preheated at 80°C for 5 min, pre-pressed at 5 MPa to exhaust, first heated to 60°C to vulcanize the self-repairing layer, then heated to 150°C to vulcanize the reinforcing layer, and finally cooled to 130°C to vulcanize the weather-resistant protective layer, and cooled to 50°C to demold to obtain the high-adhesion composite material #7.

[0092] Example 8: This example discloses a high-adhesion composite material #8 for rubber dams and a preparation method thereof.

[0093] The silicone rubber of this example is a modified silicone rubber. The rest is the same as Example 4.

[0094] The preparation method comprises the following steps:

[0095] S1, Preparation of the weather-resistant protective layer: The high-saturation nitrile rubber was plasticated at 80°C for 2 min, carbon black, nano-TiO2, and antioxidant 1010 were added and mixed at 60 rpm for 10 min, dicumyl peroxide was added and mixed for 5 min, and the sheet was cooled.

[0096] S2, Preparation of the reinforcing layer: The ethylene propylene diene rubber and styrene butadiene rubber were plasticated at 68°C for 3 min, carbon black and graphene were added and mixed at 50 rpm for 10 min, nylon fibers and aramid fibers with a length of 6-8 mm were added and mixed for 5 min, sulfur and accelerator CZ were added and mixed for 5 min before discharging.

[0097] S3, Preparation of the microcapsule self-repairing agent:

[0098] S31, Preparation of core material: mix nano-ZnO with silane coupling agent, add anhydrous ethanol, ultrasonic dispersion for 30 min at 40 kHz, stir for 2 h at 60℃, centrifugal for 10 min at 4000 rpm, wash with ethanol for 3 times, vacuum drying at 60℃ to obtain modified ZnO, mix modified ZnO with liquid polysulfide rubber, magnetic stirring for 1 h at 50℃ and 500 rpm to form a uniform suspension;

[0099] S32, Preparation of matrix material: add urea and formaldehyde into water and stir, adjust pH to 8.0-8.5, react for 1 h at 70℃ to generate transparent urea-formaldehyde prepolymer, and then reduce to room temperature;

[0100] S33, In-situ polymerization of microcapsules: add the suspension into the urea-formaldehyde prepolymer solution, add emulsifier, emulsify for 10 min at 10000 rpm to form an emulsion, add ammonium chloride to the emulsion, adjust pH to 3.0-3.5, stir at 300 rpm and 55℃ for 3 h, centrifugal for 5 min at 3000 rpm, wash the precipitate with deionized water for 3 times, and vacuum drying at 40℃ for 24 h to obtain the microcapsule self-repairing agent.

[0101] S4, Preparation of modified silicone rubber: add methyl vinyl silicone rubber and 3-aminopropyltrimethoxysilane into toluene and react for 6 h at 80℃, the mass ratio of the methyl vinyl silicone rubber to the 3-aminopropyltrimethoxysilane is 20:1, then add bismaleimide with a mass ratio of 10:1, stir for 5 min until completely dissolved, and then place in an oven at 60℃ for drying for 1.5 h to obtain the modified silicone rubber.

[0102] S5, Preparation of self-repairing layer: pass the silicone rubber through a thin passageway for 3 times at 25℃, mix with nano-SiO2, and stir uniformly at 150 rpm, and finally add the microcapsule self-repairing agent and dispersant, and slowly mix for 2 min to ensure uniform dispersion.

[0103] S6, Vacuum hot pressing vulcanization: place the rubber materials in the mold in sequence, spray waterborne polyurethane adhesive between the layers, pre-dry at 80℃ for 5 min, pre-press at 5 MPa to exhaust, first increase the temperature to 60℃ to vulcanize the self-repairing layer, then increase the temperature to 150℃ to vulcanize the reinforcing layer, and finally decrease the temperature to 130℃ to vulcanize the weather-resistant protective layer, keep pressure cooling to 50℃ to demold to obtain the high-adhesion composite material #8.

[0104] Example 9: The present embodiment discloses a high-adhesion composite material #9 for rubber dam and a preparation method thereof.

[0105] The silicone rubber of the present embodiment is a modified silicone rubber. The rest is the same as that of Example 5.

[0106] The preparation method comprises the following steps:

[0107] S1, Preparation of weather-proof layer: high saturated nitrile rubber was plasticized at 80℃ for 2 min, carbon black, nano-TiO2 and antioxidant 1010 were added in turn, and mixed at 60 rpm for 10 min, then dicumyl peroxide was added and mixed for another 5 min, and then sheeting and cooling.

[0108] S2, Preparation of modified nylon fiber: 5% silane coupling agent was mixed with 95% ethanol, 1% acetic acid was added to adjust the pH to 4-5, the nylon fiber was immersed in the treatment solution, stirred at 60℃ for 2h, dried at 80℃ for 1.5h, then vacuumized to 10 -2 Pa, then oxygen was introduced, and the surface of the nylon fiber was bombarded by plasma for 5 min under the conditions of power 50W and gas flow 20sccm, to obtain the modified nylon fiber.

[0109] S3, Preparation of reinforcing layer: EPDM and SBR were plasticized at 68℃ for 3 min, carbon black and graphene were added and mixed at 50 rpm for 10 min, then modified nylon fiber and aramid fiber with a length of 6-8mm were added and mixed for 5 min, then sulfur and accelerator CZ were added and mixed for another 5 min, and then the material was discharged.

[0110] S4, Preparation of modified silicone rubber: methyl vinyl silicone rubber and 3-aminopropyltrimethoxysilane were added to toluene and reacted at 80℃ for 6h, the mass ratio of the methyl vinyl silicone rubber to the 3-aminopropyltrimethoxysilane was 20:1, then bismaleimide was added and mixed at a mass ratio of 10:1, stirred for 5 min until completely dissolved, and then placed in an oven at 60℃ for drying for 1.5h to obtain the modified silicone rubber.

[0111] S5, Preparation of self-repairing layer: the modified silicone rubber was passed through three times at 25℃, then nano-SiO2 was added and mixed, and finally self-repairing agent and dispersing agent were added and slowly mixed for 2 min to ensure uniform dispersion.

[0112] S6, Vacuum hot pressing vulcanization: the rubber materials of each layer were sequentially placed in a mold, water-based polyurethane adhesive was sprayed between the layers, preheated at 80℃ for 5 min, pre-pressed at 5 MPa to exhaust air, first heated to 60℃ to vulcanize the self-repairing layer, then heated to 150℃ to vulcanize the reinforcing layer, and finally cooled to 130℃ to vulcanize the weather-proof layer, and then cooled to 50℃ to demold, to obtain the high-adhesion composite material #9.

[0113] Example 10: The present embodiment discloses a high-adhesion composite material #10 for rubber dam and a preparation method thereof.

[0114] The silicone rubber of the present embodiment is a modified silicone rubber. The rest is the same as Example 6.

[0115] The preparation method comprises the following steps:

[0116] S1, Preparation of weatherproofing layer: high saturated nitrile rubber is plasticated at 80℃ for 2 min, carbon black, nano-TiO2 and antioxidant 1010 are added in turn, mixing at 60 rpm for 10 min, then dicumyl peroxide is added and mixing is continued for 5 min, sheeting and cooling.

[0117] S2, Preparation of modified nylon fiber: 5% silane coupling agent is mixed with 95% ethanol, 1% acetic acid is added to adjust pH to 4-5, nylon fiber is immersed in the treatment solution, constant temperature stirring at 60℃ for 2 h, drying at 80℃ for 1.5 h, then vacuum to 10 -2 Pa, then oxygen is introduced, nylon fiber surface is plasma bombarded at power 50 W and gas flow 20 sccm for 5 min, to obtain the modified nylon fiber.

[0118] S3, Preparation of reinforcing layer: EPDM rubber and styrene-butadiene rubber are plasticated at 68℃ for 3 min, carbon black and graphene are added under mixing at 50 rpm for 10 min, modified nylon fiber and aramid fiber with length of 6-8 mm are added and mixing is continued for 5 min, then sulfur and accelerator CZ are added and mixing is continued for 5 min before discharging.

[0119] S4, Preparation of microcapsule self-repairing agent:

[0120] S41, Preparation of core material: nano-ZnO is mixed with silane coupling agent and added in anhydrous ethanol, ultrasonic dispersion at 40 kHz for 30 min, stirring at 60℃ for 2 h, centrifugation at 4000 rpm for 10 min, ethanol washing for 3 times, vacuum drying at 60℃ to obtain modified ZnO, mixing the modified ZnO with liquid polysulfide rubber, magnetic stirring at 50℃ and 500 rpm for 1 h to form a uniform suspension;

[0121] S42, Preparation of shell material: urea and formaldehyde are added in water and stirred, pH is adjusted to 8.0-8.5, reaction at 70℃ for 1 h to generate transparent urea-formaldehyde prepolymer, and the temperature is lowered to room temperature;

[0122] S43, In-situ polymerization of microcapsules: the suspension is added to the urea-formaldehyde prepolymer solution, emulsifier is added, emulsification at 10000 rpm for 10 min to form an emulsion, ammonium chloride is added to the emulsion, pH is adjusted to 3.0-3.5, constant temperature stirring at 300 rpm and 55℃ for 3 h, centrifugation at 3000 rpm for 5 min, the precipitate is washed with deionized water for 3 times, vacuum drying at 40℃ for 24 h to obtain the microcapsule self-repairing agent.

[0123] S5, Preparation of modified silicone rubber: methyl vinyl silicone rubber and 3- aminopropyltrimethoxysilane were added to toluene at 80°C for 6h, the mass ratio of methyl vinyl silicone rubber to 3-aminopropyltrimethoxysilane was 20:1, then bis-maleimide was added with a mass ratio of 10:1, stirred for 5min until completely dissolved, placed in a 60°C oven for 1.5h to dry, to obtain modified silicone rubber.

[0124] S6, Preparation of self-repairing layer: modified silicone rubber was passed through three times at 25°C, then nano-SiO2 was added and mixed, stirred uniformly at 150rpm, finally microcapsule self-repairing agent and dispersing agent were added, and slowly mixed for 2min to ensure uniform dispersion.

[0125] S7, Vacuum hot pressing vulcanization: the rubber material of each layer was sequentially placed in the mold, water-based polyurethane adhesive was sprayed between the layers, preheated at 80°C for 5min, pre-pressed at 5MPa to exhaust, first heated to 60°C to vulcanize the self-repairing layer, then heated to 150°C to vulcanize the reinforcing layer, finally cooled to 130°C to vulcanize the weather-resistant protective layer, and cooled to 50°C to demold, to obtain high-adhesion composite material #10.

[0126] Comparative Example 1: This comparative example provides a comparative high-adhesion composite material D1, which is the same as Example 10, except that nitrile rubber is used instead of high-saturation nitrile rubber in the weather-resistant protective layer, and the weather-resistant protective layer lacks dicumyl peroxide.

[0127] Comparative Example 2: This comparative example provides a comparative high-adhesion composite material D2, which is the same as Example 10, except that the self-repairing layer does not contain microcapsule self-repairing agent.

[0128] Comparative Example 3: This comparative example provides a comparative high-adhesion composite material D3, which is the same as Example 10, except that solid polysulfide rubber is used instead of liquid polysulfide rubber.

[0129] Comparative Example 4: This comparative example provides a comparative high-adhesion composite material D4, which is the same as Example 10, except that nano-MgO is used instead of nano-ZnO as the core material of the microcapsule self-repairing agent.

[0130] Comparative Example 5: This comparative example provides a comparative high-adhesion composite material D5, which is the same as Example 10, except that the core material of the microcapsule self-repairing agent does not contain KH-550 coupling agent.

[0131] Comparative Example 6: This comparative example provides a comparative high-adhesion composite material D6, which is the same as Example 10, except that ammonium sulfate is used instead of ammonium chloride as the wall material of the microcapsule self-repairing agent.

[0132] The micro crack repair test, tensile strength recovery rate test (according to the standard of ASTM D412), elongation at break recovery rate test, and interface peeling test were performed on the high adhesion composite materials #1-#10 of Examples 1-10 and the comparative high adhesion composite materials D1-D6 of Comparative Examples 1-6, and the test results are shown in Table 1.

[0133] The test steps of the micro crack repair test are as follows:

[0134] (1) A single crack with a length of 5 mm and a depth of 50 μm was drawn in the middle of the gauge section of each sample by using a diamond blade, and the crack width (W0) and depth (D0) were calibrated and measured by a laser confocal microscope with an accuracy of ±0.1 μm; (2) the sample with the crack was placed in an oven at 80°C for 1 hour, and a slight cyclic load (5% strain, frequency 1 Hz, 10 cycles) was applied to each sample; (3) the crack width (W1) and depth (D1) after repair were measured by a laser confocal microscope; and (4) the formula was used to calculate: width repair rate = (1-W0 / W1) x 100%, and depth repair rate = (1-D0 / D1) x 100%.

[0135] The tensile strength recovery rate test steps are as follows: the tensile strengths σ0 and σ1 before and after repair were tested according to ASTM D412, and the formula was used to calculate: strength repair rate = σ0 / σ1 x 100%.

[0136] The elongation at break recovery rate test steps are as follows: the tensile strengths F0 and F1 before and after repair were tested according to ASTM D412, and the formula was used to calculate: strength repair rate = F0 / F1 x 100%.

[0137] Table 1

[0138]

[0139] From the data of Examples 1-3, especially the data of Example 3, it can be seen that by reasonable matching of the constituent materials of the high-adhesion composite material of the application, the high-adhesion composite material for rubber dams of the application has excellent performance in micro-crack repair rate, tensile strength recovery rate, elongation at break recovery rate, and interfacial peeling strength. The reason is that the double bond content of high-saturation nitrile rubber in the weather-resistant protective layer is extremely low, which significantly reduces the oxidative degradation caused by ozone and ultraviolet light. The peroxide can decompose to generate free radicals at high temperatures, which can initiate cross-linking reactions between the molecular chains of high-saturation nitrile rubber, and through the formation of a three-dimensional network structure, the tensile strength, elastic modulus, and deformation resistance of the material are improved. In the reinforcing layer, the aging resistance of the ethylene-propylene-diene rubber is strong, and the aramid fiber has high tensile strength and can bear the main tensile stress to prevent excessive deformation of the dam body. The nylon fiber can absorb impact energy and delay crack propagation through plastic deformation, forming a reinforcing network with the aramid fiber. Graphene can form a three-dimensional network in the ethylene-propylene-diene rubber and styrene-butadiene rubber matrix, which can hinder crack propagation through the "crack pinning effect" and improve the tear resistance, while also improving the thermal conductivity to avoid local overheating. In the self-repairing layer, silicone rubber serves as the main body of the self-repairing layer, providing high elasticity and flexibility to meet the deformation requirements of the dam. Nano-SiO2 particles are dispersed in the modified silicone rubber matrix, which can inhibit the low-temperature embrittlement of the molecular chains through physical cross-linking points, improve the elasticity of the material at low temperatures, and increase the hardness and wear resistance of the rubber matrix. Nano-SiO2 particles can also cooperate with the self-repairing agent to delay the crack propagation path and provide time for self-repairing.

[0140] Compared with Example 3, Example 4 uses the microcapsule self-repairing agent of the application, and the micro-crack repair rate, tensile strength recovery rate, and elongation at break recovery rate of the high-adhesion composite material #4 obtained in Example 4 are further improved. This is because the silane coupling agent in the microcapsule self-repairing agent of the application hydrolyzes to form silanol (-Si(OH)3) in ethanol, which condenses with the hydroxyl groups (-OH) on the surface of ZnO to form Si-O-Zn covalent bonds, and introduces amino groups (-NH2) on the surface of ZnO, which improves the compatibility of ZnO with polysulfide rubber (containing -SH), prevents the agglomeration of nanoparticles, and ensures the homogeneous dispersion of the core material. The amino groups on the surface of ZnO modified by the silane coupling agent form stable complexes with the thiol groups (-SH) of the liquid polysulfide rubber through hydrogen bonding. During the crack propagation process, the stress at the crack tip triggers the rupture of the microcapsule, releasing liquid polysulfide rubber and modified nano-ZnO. The modified nano-ZnO acts as a cross-linking catalyst and reacts with the liquid polysulfide rubber to form a polysulfide network (-S-S- bond), rapidly filling the micro-cracks.

[0141] Example 5 and Example 3, Example 6 and Example 4, the modified nylon fiber is used, the interfacial peeling strength of the high adhesion composite #5 and the high adhesion composite #6 obtained is improved, because the polar groups (-NH2, -OH) on the surface of the modified nylon fiber can form chemical bonding with the rubber matrix, preventing interlayer peeling, improving the chemical adhesion with the rubber, and improving the adhesion of the composite.

[0142] Example 7 and Example 3, Example 8 and Example 4, Example 9 and Example 5, and Example 10 and Example 6, all use modified silicone rubber,

[0143] The microcrack repair rate, tensile strength recovery rate, and elongation at break recovery rate of the high adhesion composites #7-#10 obtained are improved, because the reversible crosslinking bonds in the modified silicone rubber can dissociate when the temperature is higher than 60℃, soften the material, rearrange the molecules at the crack interface, and the reversible crosslinking bonds can recombine and close the cracks after cooling.

[0144] Comparative Example 1 and Example 10, nitrile rubber is selected instead of high-saturation nitrile rubber in the weather protection layer, and the weather protection layer lacks dicumyl peroxide. The properties of the comparative high adhesion composite D1 obtained all decrease to varying degrees, because the double bond content of high-saturation nitrile rubber is very low, which can significantly reduce the oxidative degradation induced by ozone and ultraviolet light. Dicumyl peroxide can decompose to generate free radicals at high temperatures, initiate crosslinking reactions between the molecular chains of high-saturation nitrile rubber, and improve the tensile strength, elastic modulus, and deformation resistance of the material by forming a three-dimensional network structure.

[0145] Comparative Example 2 and Example 10, the self-healing layer does not contain microcapsule self-healing agent, and the properties of the comparative high adhesion composite D2 obtained all decrease significantly, because the microcapsule self-healing agent can be triggered to break and release liquid polysulfide rubber and modified nano-ZnO according to the stress at the crack tip. Modified nano-ZnO acts as a crosslinking catalyst and reacts with liquid polysulfide rubber to form a polysulfide network (-S-S- bond), rapidly filling microcracks.

[0146] Comparative Example 3 and Example 10, solid-state polysulfide rubber is selected instead of liquid polysulfide rubber, and the properties of the comparative high adhesion composite D3 obtained decrease, because liquid polysulfide rubber contains thiol (-SH) end groups and can be vulcanized at room temperature, but solid-state polysulfide rubber has a main chain containing sulfur-sulfur bonds and needs to be vulcanized at high temperatures. It also has poor flowability and tends to agglomerate with nanoparticles, affecting the homogeneous dispersion of the core material.

[0147] Compared with Example 10, the micro-crack repair rate, tensile strength recovery rate and elongation at break recovery rate of the comparative high-adhesion composite D4 obtained by using nano-MgO instead of nano-ZnO in the core material of the microcapsule self-repairing agent are all decreased, because the vulcanization of the liquid polysulfide rubber needs to react with the metal oxide through the mercaptan group, and the formation efficiency of the cross-linked structure by magnesium oxide is lower, which cannot replace zinc oxide to play a key role.

[0148] Compared with Example 10, the performance of the comparative high-adhesion composite D5 obtained by not including KH-550 coupling agent in the core material of the microcapsule self-repairing agent is decreased, because the silane coupling agent is hydrolyzed to form silanol (-Si(OH)3) in ethanol, the silanol is condensed with the hydroxyl group (-OH) on the surface of ZnO to form Si-O-Zn covalent bond, and the amino group (-NH2) is introduced on the surface of ZnO, which improves the compatibility of ZnO and polysulfide rubber (containing -SH), prevents the agglomeration of nanoparticles, and ensures the homogeneous dispersion of the core material.

[0149] Compared with Example 10, the performance of the comparative high-adhesion composite D6 obtained by using ammonium sulfate instead of ammonium chloride in the wall material of the microcapsule self-repairing agent is decreased, because the hydrolysis of ammonium chloride generates H + , which reduces the pH and activates the condensation reaction of methylol urea, although the hydrolysis of ammonium sulfate also generates an acidic environment, but the sulfate radical (SO4 2- ) in ammonium sulfate may form a hydrogen bond or complex with the hydroxyl group in methylol urea, which hinders the progress of the condensation reaction.

[0150] Therefore, the materials that are missing or replaced cannot play a role in the high-adhesion composite, but rather reduce the performance of the high-adhesion composite, so each component cannot be replaced by other materials at will.

[0151] The above are preferred embodiments of the present application, which do not limit the protection scope of the present application, therefore: any equivalent changes made on the structure, shape, principle of the present application should be covered within the protection scope of the present application.

Claims

1. A high-adhesion composite material for rubber dams, characterized in that, The high-adhesion composite material used in the rubber dam comprises an outer weather-resistant protective layer, a middle reinforcing layer, and an inner self-healing layer. By weight, the weather-resistant protective layer comprises 90-110 parts of high-saturation nitrile rubber, 23-28 parts of carbon black N550, 3-8 parts of nano TiO2, 1-3 parts of antioxidant 1010, and 2-3 parts of dicumyl peroxide; the reinforcing layer comprises 60-80 parts of ethylene propylene diene monomer (EPDM) rubber, 25-35 parts of styrene-butadiene rubber, 13-15 parts of nylon fiber, 10-12 parts of aramid fiber, 12-15 parts of carbon black, 0.5-1.5 parts of graphene, 1-2 parts of sulfur, and 0.5-1.5 parts of accelerator CZ; and the self-healing layer comprises 90-100 parts of silicone rubber, 5-10 parts of nano SiO2, 5-8 parts of self-healing agent, and 0.1-0.3 parts of dispersant. The silicone rubber is a modified silicone rubber. The preparation steps of the modified silicone rubber are as follows: methyl vinyl silicone rubber and 3-aminopropyltrimethoxysilane are added to toluene and reacted at 75-85℃ for 5-7 hours. The mass ratio of methyl vinyl silicone rubber to 3-aminopropyltrimethoxysilane is 18-22:

1. Then, bismaleimide is added and mixed at a mass ratio of 10-12:

1. The mixture is stirred for 3-7 minutes until completely dissolved and then dried in an oven at 55-60℃ for 1-2 hours to obtain the modified silicone rubber.

2. The high-adhesion composite material for rubber dams according to claim 1, characterized in that, The self-healing agent is a microcapsule self-healing agent, which comprises a core material of 30-32% by mass, a wall material of 68-70% by mass, and an emulsifier of 0.2-0.3%. The core material comprises liquid polysulfide rubber, nano-ZnO, and a silane coupling agent, with a mass ratio of 8-10:1:0.1-0.

2. The wall material comprises urea, formaldehyde, ammonium chloride, and water, with a mass ratio of 1:1.2-1.5:0.05-0.1:9-10.

3. A high-adhesion composite material for rubber dams according to claim 1 or 2, characterized in that, The nylon fiber is a modified nylon fiber. The preparation steps of the modified nylon fiber are as follows: 5% silane coupling agent is mixed with 95% ethanol, 1% acetic acid is added to adjust the pH to 4-5, the nylon fiber is immersed in the treatment solution, stirred at a constant temperature of 50-70℃ for 1-3 hours, dried at 75-85℃ for 1-2 hours, and then vacuumed to 10... -2 After Pa, oxygen is introduced, and the surface of the nylon fiber is bombarded with plasma for 3-7 minutes at a power of 45-55W and a gas flow rate of 18-22 sccm to obtain the modified nylon fiber.

4. A method for preparing a high-adhesion composite material for rubber dams as described in any one of claims 1-3, characterized in that, The preparation method includes the following steps: Preparation of weather-resistant protective layer: High-saturated nitrile rubber is plasticized at 75-85℃ for 1-3 min, carbon black, nano TiO2 and antioxidant 1010 are added in sequence, and the mixture is mixed at 55-65 rpm for 8-12 min. Then dicumyl peroxide is added and the mixture is continued to be mixed for 3-7 min. The sheet is then cooled. Preparation of the reinforcing layer: EPDM rubber and styrene-butadiene rubber are plasticized at 65-70℃ for 1-5 min, carbon black and graphene are added at 45-55 rpm and mixed for 8-12 min, nylon fiber and aramid fiber with a length of 6-8 mm are added and mixed for 3-7 min, then sulfur and accelerator CZ are added and mixed for 3-7 min before discharge. Preparation of self-healing layer: Silicone rubber is passed through a thin tube 2-3 times at 20-30℃, nano-SiO2 is added and mixed evenly, stirred evenly at 100-150rpm, and finally self-healing agent and dispersant are added, and slowly kneaded for 3-5min. Vacuum hot-press vulcanization: Lay each layer of rubber material into the mold in sequence, spray water-based polyurethane adhesive between each layer, pre-bake at 75-85℃ for 3-7 minutes, pre-press at 4-6MPa to degas, first raise the temperature to 60℃ to vulcanize the self-healing layer, then raise it to 150℃ to vulcanize the intermediate layer, and finally lower the temperature to 130℃ to vulcanize the outer layer. Hold the pressure and cool to 50℃ to demold to obtain a high-adhesion composite material.

5. The method for preparing a high-adhesion composite material for rubber dams according to claim 4, characterized in that, The preparation method further includes a step of preparing a microcapsule self-repairing agent, the preparation steps of which are as follows: Preparation of core material: Nano-ZnO is mixed with silane coupling agent, added to anhydrous ethanol, ultrasonically dispersed at 35-45 kHz for 25-35 min, stirred at 55-65 ℃ for 1-3 h, centrifuged at 3500-4500 rpm for 8-12 min, washed with ethanol 2-3 times, and vacuum dried at 55-65 ℃ to obtain modified ZnO. Modified ZnO is mixed with liquid polysulfide rubber and magnetically stirred at 45-55 ℃ and 450-550 rpm for 0.5-1.5 h to form a uniform suspension. Preparation of wall material: Add urea and formaldehyde to water and stir, adjust the pH to 8.0-8.5, react at 65-75℃ for 0.5-1.5h to generate transparent urea-formaldehyde prepolymer, and then cool to room temperature; In-situ polymerization of microcapsules: The suspension was added to the urea-formaldehyde prepolymer solution, an emulsifier was added, and emulsification was carried out at 10,000-11,000 rpm for 8-12 min to form an emulsion. Ammonium chloride was added to the emulsion to adjust the pH to 3.0-3.

5. The mixture was stirred at 250-350 rpm and 50-60℃ for 2-4 h, centrifuged at 2500-3500 rpm for 3-7 min, and the precipitate was washed 2-3 times with deionized water and vacuum dried at 35-45℃ for 22-26 h to obtain the microcapsule self-healing agent.

6. A rubber dam, characterized in that, The rubber dam uses a high-adhesion composite material for rubber dams as described in any one of claims 1-3, or a high-adhesion composite material prepared using the preparation method of the high-adhesion composite material for rubber dams as described in any one of claims 4-5.

7. The application of a rubber dam as described in claim 6 in the river management industry, agricultural irrigation industry, flood control and tide blocking industry, shipping and transportation industry, and in the construction of rubber dams under high water pressure environment.

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