CN118006275A - Heat-conducting corrosion-resistant polyurea sealant and preparation method and application thereof - Google Patents

Abstract

The invention relates to the technical field of sealant preparation, in particular to a heat-conducting corrosion-resistant polyurea sealant, and a preparation method and application thereof. The heat-conducting corrosion-resistant polyurea sealant is prepared from the following raw materials in parts by weight: 5-10 parts of modified graphene material, 80-155 parts of rapid film forming component, 65-111 parts of adhesion material, wherein the graphene material is selected from graphene or graphene oxide, and a modifier of the modified graphene material is a silane coupling agent. According to the invention, by introducing the modified graphene material, the corrosion resistance and the heat conduction performance of the polyurea sealant can be obviously improved; the heat-conducting corrosion-resistant polyurea sealant has the advantages of low preparation cost and stable performance, can realize quick plugging of the radiator under the condition of no shutdown, and is suitable for quick repair of leakage of the offshore wind power and coastal wind power radiator.

Description

Heat-conducting corrosion-resistant polyurea sealant and preparation method and application thereof

Technical Field

The invention belongs to the technical field of sealant preparation, and relates to a heat-conducting corrosion-resistant polyurea sealant, and a preparation method and application thereof.

Background

As a pollution-free and sustainable green energy source, wind power generation brings great convenience to the production and life of people, and compared with land wind power, the energy benefit of the offshore wind power resource is 20 percent higher, and the wind power generation system has the advantages of high wind speed, large electric quantity, stable operation, suitability for large-scale development and the like. In recent years, the development of the offshore wind power industry in China is rapid, and the offshore wind power industry has entered a large development stage of large scale and commercialization, however, the marine environment is a typical high-temperature, high-humidity, high-salt and strong-radiation three-high-one-strong corrosion environment, the corrosion risk level is higher, and the method has a great threat to the structural safety and service life of an offshore wind power generation infrastructure.

At present, corrosion prevention research of offshore wind power equipment is mainly focused on corrosion prevention of parts such as a draught fan underwater foundation, a tower steel structure, a draught fan cabin, a draught fan blade and the like, the adopted corrosion prevention technology mainly comprises coating corrosion prevention, cathode protection, composite coating corrosion prevention, reserved corrosion allowance and the like, the corrosion prevention research of a radiator is less, a generator, a gear box, a frequency converter and the like are used as core components of the wind power generator, a large amount of heat is generated in the operation process, and a cooling system-the radiator is required to be equipped for ensuring stable operation of offshore wind power. The radiator, which is an important component for ensuring stable and reliable operation of the wind turbine, is generally disposed outside the wind turbine, and is divided into a heat transfer module, a water cooling pipe, a fan, a radiator core, and a radiator pressure plate. The air radiator core has large contact area with air, is a main heat exchange device, and corrosion of the air radiator core can influence the overall heat transfer performance of the system, so that cooling medium leakage is caused, and the cooling medium is harmful to the operation of the system, therefore, the preparation process and the corrosion resistance of the air radiator need to be fully researched. In order to solve the problem, an anti-corrosion coating is generally sprayed on the transformer body of the radiator and the outer wall and the inner wall of the radiator in engineering to enhance the corrosion resistance of the radiator.

The traditional coating on the radiator usually adopts a matched system of a curtain-coated epoxy glass flake coating and an aliphatic polyurethane finish paint, the design service life is generally 25 years, however, the operation working condition of the offshore wind power radiator is complex, and the offshore wind power radiator has a plurality of leakage points after 5 years of operation, and can not effectively prevent leakage even though a plurality of coatings are adopted for repeated repair. The corrosion-resistant coating is continuously corroded by chloride ions in the air under the high-temperature and high-humidity environment, gradually enters the coating and is corroded to the metal substrate, the thickness of the radiator substrate is only 1mm, the radiator substrate is very easy to etch through, the operation and maintenance of the fan is simply to coat paint on leakage points, the paint coating has little anti-leakage effect, and the damage to metal caused by external chloride ions can not be blocked continuously; meanwhile, the cooling liquid of the radiator is in a higher temperature environment (generally between 50 and 80 ℃) under the working state, the circulating flow of the cooling liquid in the radiator can simultaneously erode radiator fins and form pressure difference at leakage points, so that once a coating is corroded and cracked, the leakage speed can be continuously increased, and due to the pressure difference and the running temperature, the conventional coating cannot be quickly formed into films, and the leakage points are difficult to effectively seal. Because offshore wind power is far away from land, the operation and maintenance difficulty of equipment can be increased, if the equipment is stopped for maintenance, the loss is serious, so that a rapid plugging technology of a radiator can be realized under the condition of no stopping, the operation working condition of the offshore wind power radiator is complex, the research on the influence of flow, pressure, temperature and the like on corrosion is shallow, and the plugging technology of the offshore wind power radiator is more freshly reported.

In addition, the heat dissipation efficiency of the radiator has an important significance on the reliability of the power transformer system, the traditional coating on the radiator is designed for improving the corrosion resistance of the radiator, and researches show that the corrosion-resistant coating with poor heat conductivity greatly reduces the overall heat conductivity of the plate radiator, so that the heat conductivity coefficient of the radiator surface corrosion-resistant coating is also considered in the design.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides the heat-conducting corrosion-resistant polyurea sealant, and the preparation method and the application thereof, and provides the special polyurea sealant for repairing the leakage of the offshore wind power.

In order to achieve the above purpose, the technical scheme of the invention is as follows:

A heat-conducting corrosion-resistant polyurea sealant is prepared from the following raw materials in parts by weight: compared with the prior art, the modified graphene material is applied to the preparation of the heat-conducting corrosion-resistant polyurea sealant, and the heat-conducting corrosion-resistant polyurea sealant is applied to the realization of the leakage repair of the offshore wind power radiator.

Preferably, the graphene material is selected from graphene or graphene oxide, a modifier of the modified graphene material is a silane coupling agent, and the graphene material can be applied to the application.

Preferably, the silane coupling agent is selected from bis [ gamma- (triethoxysilyl) propyl ] tetrasulfide silane, 3-aminopropyl triethylsilane, (3-glycidoxy) trimethoxysilane or gamma- (methacryloyloxy) propyl trimethoxysilane, the mass ratio of the silane coupling agent to graphene is 1:1-6, the silane coupling agent is used for modifying the graphene material, improving the dispersibility of the graphene material in the rapid film forming component and the adhesion material, and improving the combination of the rapid film forming component, the adhesion material and the graphene material.

Preferably, the adhesion material is prepared from the following raw materials in parts by weight: 40-70 parts of amino polyether, 15-20 parts of modified resin, 1-3 parts of stabilizer, 1-4 parts of dispersing agent, 5-8 parts of zinc powder, 1-2 parts of anti-sedimentation wax, 1 part of pigment and 1-3 parts of corrosion inhibitor.

Preferably, the modified resin is selected from one or more of fluorine modified aspartic acid ester F520, F220, F420, F2850 and F421, the stabilizer is selected from tartaric acid or benzoic acid, the dispersing agent is selected from one or more of calcium phosphate, aluminum phosphate, polysiloxane, silicone, ammonium polyacrylate and polyacrylate, and the corrosion inhibitor is selected from one or more of sodium molybdate, organic phosphonic acid, azyl benzothiazole, benzotriazole and amino acid.

Preferably, the adhesive material is prepared as follows: the amino polyether, the modified resin, the stabilizer, the dispersant, the zinc powder, the dustproof wax, the pigment and the corrosion inhibitor are stirred and mixed for 0.5 to 1 hour, and then the adhesive material is obtained through grinding and filtering.

Preferably, the adhesive material is prepared as follows: stirring and mixing amino polyether, modified resin, stabilizer, dispersant, zinc powder, dustproof wax, pigment and corrosion inhibitor for 0.5-1h, grinding and filtering to remove pigment with large granularity and modified graphene particles, and obtaining the adhesion material.

Preferably, the rapid film forming component is polyurethane, and the polyurethane is prepared from the following raw materials in parts by weight: 30-50 parts of polyalcohol, 40-70 parts of polyisocyanate and 10-35 parts of amino chain extender;

The polyalcohol is selected from one or more of butanediol, neopentyl glycol, diethylene glycol, 1, 4-cyclohexanediol, dipropylene glycol, 2, 4-diethyl-1, 5-pentanediol, 2-ethyl-1, 3-hexanediol, trimethylolpropane and pentaerythritol;

The amino chain extender is one or a combination of several selected from ethylenediamine, adipic acid dihydrazide and N, N _, -dihydroxyl (diisopropyl) aniline;

The polyisocyanate is selected from one or more of toluene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate and cyclohexane dimethylene diisocyanate.

Preferably, the rapid prototyping composition is prepared according to the following steps:

Mixing dehydrated polyol, polyisocyanate and amino chain extender in nitrogen environment, and carrying out crosslinking polymerization at 55-85 ℃ for 2h, wherein the dehydration condition of the polyol is as follows: dehydrating for 1h at 75-90 ℃ to obtain polyurethane.

The invention also provides a preparation method of the heat-conducting corrosion-resistant polyurea sealant, which is characterized by comprising the following steps:

Dispersing a silane coupling agent in a solvent, hydrolyzing under an acidic condition, adjusting the pH value to be neutral, and reacting with a graphene material to obtain a modified graphene material;

And mixing the rapid film forming component, the modified graphene material and the adhesion material to obtain the heat-conducting corrosion-resistant polyurea sealant.

The application also protects the application of the heat-conducting corrosion-resistant polyurea sealant in preparing the sealant for repairing the leakage of the offshore wind power radiator, and the heat-conducting corrosion-resistant polyurea sealant is directly coated on the leakage of the coating of the offshore wind power radiator when in use.

Compared with the prior art, the invention has the beneficial effects that:

1. The unique carbon six-membered ring structure of the graphene endows the graphene with excellent physicochemical properties, particularly the thermal conductivity at room temperature is about 5000W/(m.K), and meanwhile, the graphene has excellent hydrophobic and oleophobic properties, can play a role in physical isolation in a coating, and has the effect of remarkably improving the anti-corrosion property and heat dissipation capability of the coating; the heat-conducting corrosion-resistant polyurea sealant provided by the invention is a novel anti-leakage repair material for wind power radiators, and can achieve the purpose of rapid repair without shutdown. In addition, the graphene has excellent room temperature heat conductivity, so that the heat conduction and dissipation efficiency of the radiator coating is improved, the heat dissipation of the radiator is accelerated, the service life of the radiator can be further prolonged, the operation and maintenance cost is reduced, and the energy resource utilization efficiency can be greatly improved.

As an important field of carbon emission reduction in China, the iron and steel industry faces the challenges of 'relative constraint' of carbon emission intensity, 'absolute constraint' of total carbon emission amount and serious 'carbon economy'. The corrosion resistance of the radiator is improved, so that huge carbon emission caused by loss is reduced, effective carbon emission control is performed from the source, and contribution is made to carbon peak carbon neutralization.

2. The heat-conducting corrosion-resistant polyurea sealant consists of a rapid film forming component, a modified graphene material and an adhesion material, wherein the rapid film forming component, the modified graphene material and the adhesion material are mutually mixed, and the rapid solidification effect of the sealant is improved by introducing the rapid film forming active component, so that rapid film forming at a leakage point is realized, and a rapid plugging effect on a heat dissipation medium is realized; meanwhile, modified graphene is designed and introduced, so that on one hand, the corrosion resistance of the sealant is improved, on the other hand, the sealant is endowed with excellent heat conductivity, and the defect of poor heat dissipation efficiency of the traditional coating is overcome; meanwhile, the adhesive force of the coating is reduced by taking the introduction of graphene into consideration, and the effective components for improving the adhesive force are added into the formula, so that the heat dissipation efficiency of the radiator is effectively improved while the leakage points are rapidly plugged without stopping the machine;

In addition, the heat-conducting corrosion-resistant polyurea sealant designed by the invention has low manufacturing cost and small pollution, and the operation method for carrying out the radiator leakage repair technology by using the heat-conducting corrosion-resistant polyurea sealant is simple, time-saving and labor-saving.

3. The adhesion material consists of amino polyether, modified resin, stabilizer, dispersant, zinc powder, anti-sedimentation wax, pigment and corrosion inhibitor, wherein both the amino polyether and the modified resin can react with isocyanate ions of polyurethane, so that the crosslinking of the polyurethane is promoted, and the polymerization effect is improved; the stabilizer is used for preventing the heat-conducting corrosion-resistant polyurea sealant from precipitating or deteriorating; the dispersing agent ensures the structural stability of the whole heat-conducting corrosion-resistant polyurea sealant and prevents agglomeration; zinc powder improves the overall corrosion resistance of the material; the pigment is not easy to disperse, so that the anti-sedimentation wax is adopted to ensure the uniform dispersion of the pigment; the corrosion inhibitor is convenient to combine with rust on one hand, reduces the treatment requirement on the surface of the rust, and on the other hand, effectively prevents external Cl ^- from further penetrating into the wind power radiator, and reduces the corrosion of the external Cl ^- to the wind power radiator.

Drawings

FIG. 1 is a schematic diagram of the preparation of a heat-conductive corrosion-resistant polyurea sealant according to an embodiment of the present invention;

Fig. 2 is a diagram of a metal material corrosion resistance study using the heat conductive and corrosion resistant polyurea sealant according to example 1 of the present invention.

Detailed Description

The following detailed description of specific embodiments of the invention is, but it should be understood that the invention is not limited to specific embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention. The experimental methods described in the examples of the present invention are conventional methods unless otherwise specified.

The ocean is the most severe natural corrosion environment, the corrosion of the sea is a considerable threat to the wind generating set, the corrosion prevention work is good, and the construction cost of the whole life is much lower. The offshore wind power infrastructure and engineering equipment are largely composed of steel structures, marine corrosion protection is achieved, service life of the offshore wind turbine generator is prolonged, energy resource utilization efficiency can be greatly improved, effective carbon emission control is achieved from the source, and great contribution is made to carbon peak carbon neutralization targets.

The existing offshore wind power radiator mainly refers to the design form of an onshore wind turbine generator, and mainly comprises two modes of forced air cooling and liquid cooling. Because the offshore wind turbine has a severe service environment and strong corrosiveness, the forced air cooling mode is not common in offshore wind power radiators, and more adopts a heating component to be placed in a closed circulating liquid loop, and the cooling liquid exchanges heat with an external cold source through the radiator in the loop; the air radiator of the high-power offshore wind turbine adopts a mode of combining natural cooling and forced air cooling, so that the energy consumption can be further reduced while the cooling requirement of the wind turbine is met.

The box-type transformer is an important device for energy transfer of a wind power plant, is used as a key device for boosting a wind turbine generator, and mostly is used for boosting low-voltage 400V and 690V to 10kV and 35kV through the boosting transformer and conveying the low-voltage 400V and 690V to a power grid, so that the function of connecting a tie bridge up and down in the wind power plant is achieved. As a primary master device of the new energy station, the operation must be stable and reliable. The loss generated during the operation of the oil immersed transformer is converted into heat, so that the temperature rise inside the transformer is caused, and if the heat cannot be effectively emitted, overheat can occur, so that the performance of an internal insulating junction material is deteriorated; the plate radiator has the advantages of low cost, simple structure, high radiating efficiency and the like, is key equipment for ensuring normal production of the transformer and adjusting the temperature of a process medium, and has heat exchange performance which directly influences the service life of metal devices such as internal windings of the transformer. The fin type heat exchanger is a main stream heat radiator for the current transformer, the durability of the fin type heat radiating fins relates to the normal operation of the transformer, the fin type heat exchanger is formed by welding a plurality of heat radiating fins with an upper oil collecting pipe and a lower oil collecting pipe, and the fin type heat exchanger is generally symmetrically arranged on two sides of a transformer body; when the transformer operates, heat generated by the structures such as windings, iron cores and the like heats transformer oil in a heat conduction and heat convection mode, the density of the heated transformer oil becomes smaller and floats upwards to enter the upper oil collecting pipe, then flows downwards in the oil duct of the radiating fin under the action of gravity and dissipates the heat into the air, the cooled transformer oil is obtained, and the cooled transformer oil is collected to the lower oil collecting pipe and reenters the transformer body.

The heat transfer process of the transformer oil in the finned radiator consists of three parts, wherein the convection material change of the transformer oil on the ① transformer oil side and the inner wall of the radiator is a carbon steel plate with good heat conduction performance and thickness of only 1mm, and the transformer is heated for a long time because of the relatively severe outdoor environment; ② Heat conduction from the inner wall of the radiator to the outer wall of the radiator; ③ The fin type radiator used in the heat exchange engineering of convection and radiation of the radiator and air is corroded by acid, alkali and salt, so that the oil leakage phenomenon is easy to occur when the radiating fins of the extremely thin fin type radiator are corroded, and if the radiating fins are not timely found, large-area power failure and fire disaster can be possibly caused. Therefore, corrosion problems have become a significant safety hazard in the operation and use of transformers.

The invention provides a heat-conducting corrosion-resistant polyurea sealant based on the fast plugging of a radiator and the improvement of heat-conducting corrosion-resistant performance under the condition of no shutdown from the aspect of being applied to the anti-leakage repair of an offshore wind power radiator;

the heat-conducting corrosion-resistant polyurea sealant takes polyurethane as a main component, has a rapid film forming function, forms a stable structure after the amino polyether, the modified resin and the polyurethane are crosslinked, has strong sealing property, can effectively block leakage points in application, and effectively block external chloride ions, thereby solving the problem of realizing rapid plugging of a radiator under the condition of no shutdown;

Compared with the traditional coating of the radiator, the graphene material is creatively adopted, and the graphene coating has the corrosion resistance of the traditional coating and also has the heat conduction performance, so that the service life of the plate radiator is prolonged; according to the application, the modified graphene material, the rapid film forming component and the adhesion material are mixed, the graphene material has excellent heat conduction and corrosion resistance, and the modifier silane coupling agent improves the dispersibility and stability of the graphene material, so that the blending of the modified graphene material, the rapid film forming component and the adhesion material is promoted, and the heat conduction and corrosion resistance polyurea sealant has excellent heat conduction and corrosion resistance.

The following examples are used to further illustrate the technical scheme, and the specific examples are as follows:

Example 1

A preparation method of a heat-conducting corrosion-resistant polyurea sealant comprises the following steps:

(1) Preparation of modified graphene materials: the volume ratio is 90:5 adding absolute ethyl alcohol and deionized water into a beaker, uniformly mixing to obtain a solvent, adding 50 parts by volume of silane coupling agent bis [ gamma- (triethoxysilyl) propyl ] tetrasulfide into the solvent, regulating the pH value to be 4 by adding glacial acetic acid and ammonia water, promoting the hydrolysis of the silane coupling agent under an acidic condition, hydrolyzing at 40 ℃ for 18 hours, regulating the pH value to be 7, regulating the solution to be neutral, enabling the hydrolyzed silane coupling agent to react with graphene more conveniently, adding 100 parts of graphene, stirring at 80 ℃ for 10 hours, enabling a siloxane bond generated by the hydrolysis of the coupling agent to react with the hydroxyl of the graphene to form a Si-O-Si structure, centrifuging at 3000r/min for 2 hours to separate out solid, washing the solid, and vacuum drying at 80 ℃ to obtain a modified graphene material which can remarkably improve the corrosion resistance and the heat conducting property of polyurea sealant;

(2) And (2) preparing a component A: heating 30 parts of polyol 1, 4-cyclohexanediol to 90 ℃ in a nitrogen environment, dehydrating for 1h, cooling to 45 ℃, adding 50 parts of polyisocyanate isophorone diisocyanate and 20 parts of amino chain extender ethylenediamine, heating to 80 ℃ for crosslinking reaction for 2h, stopping the reaction after determining NCO value by a dibutylamine titration method, and performing reduced pressure rotary evaporation to obtain a rapid film forming component;

(3) Preparation of component B: 40 parts of aminopolyether, 1 part of modified resin fluorine modified aspartic acid ester F52015 parts, 1 part of stabilizer tartaric acid, 2 parts of dispersing agent calcium phosphate, 5 parts of zinc powder, 1 part of anti-sedimentation wax, 1 part of pigment and 2 parts of corrosion inhibitor sodium molybdate are mixed, stirred and dispersed for 0.5 hour, and the mixture is ground and filtered after uniform mixing to obtain an adhesion material;

the weight portions are as follows: 80 parts of rapid film forming components, 5 parts of modified graphene materials and 65 parts of adhesion materials are mixed to obtain the heat-conducting corrosion-resistant polyurea sealant.

Example 2

A preparation method of a heat-conducting corrosion-resistant polyurea sealant comprises the following steps:

(1) Preparation of modified graphene materials: the volume ratio is 90:5, adding absolute ethyl alcohol and deionized water into a beaker, uniformly mixing to obtain a solvent, adding 50 parts by volume of silane coupling agent 3-aminopropyl triethylsilane into the solvent, regulating the pH value to be 4 by adding glacial acetic acid and ammonia water, promoting the hydrolysis of the silane coupling agent, regulating the pH value to be 7 after the hydrolysis is carried out for 20 hours at 40 ℃, regulating the solution to be neutral, enabling the hydrolyzed silane coupling agent to react with graphene more conveniently, adding 250 parts of graphene, stirring for 10 hours at 80 ℃, enabling a silicon-oxygen bond generated by the hydrolysis of the coupling agent to react with hydroxyl of the graphene to form a Si-O-Si structure, centrifuging for 2 hours at 3000r/min, washing, and vacuum drying at 80 ℃ to obtain a modified graphene material, wherein the modified graphene material can obviously improve the corrosion resistance and the heat conducting property of the polyurea sealant;

(2) And (2) preparing a component A: heating 40 parts of polyalcohol 2, 4-diethyl-1, 5-pentanediol to 75 ℃ in a nitrogen environment, dehydrating for 1h, then cooling to 45 ℃, adding 40 parts of polyisocyanate hexamethylene diisocyanate and 35 parts of amino chain extender adipic acid dihydrazide, heating to 55 ℃ for reacting for 2h, stopping the reaction after determining NCO value by a dibutylamine titration method, and performing reduced pressure rotary evaporation to obtain a rapid film forming component;

(3) Preparation of component B: 60 parts of aminopolyether, 2 parts of modified resin fluorine modified aspartic acid ester F42020 parts of stabilizer tartaric acid, 4 parts of dispersing agent silicone, 7 parts of zinc powder, 1.5 parts of anti-sedimentation wax, 1 part of pigment and 1 part of corrosion inhibitor azyl benzothiazole are stirred and dispersed for 0.5 hour, and the materials are ground and filtered after being uniformly mixed to obtain an attachment material;

The weight portions are as follows: 100 parts of rapid film forming components, 8 parts of modified graphene materials and 100 parts of adhesion materials are mixed to obtain the heat-conducting corrosion-resistant polyurea sealant.

Example 3

A preparation method of a heat-conducting corrosion-resistant polyurea sealant comprises the following steps:

(1) Preparation of modified graphene materials: the volume ratio is 90:5, adding absolute ethyl alcohol and deionized water into a beaker, uniformly mixing to obtain a solvent, adding 50 parts by volume of silane coupling agent (3-glycidoxy) trimethoxysilane into the solvent, regulating the pH value to be 4 by adding glacial acetic acid and ammonia water, promoting the hydrolysis of the silane coupling agent, regulating the pH value to be 7 after the hydrolysis is carried out at 40 ℃ for 18 hours, regulating the solution to be neutral, enabling the hydrolyzed silane coupling agent to react with graphene more conveniently, adding 300 parts of graphene, stirring for 10 hours at 80 ℃, enabling a silicon-oxygen bond generated by the hydrolysis of the coupling agent to react with hydroxyl of the graphene to form a Si-O-Si structure, centrifuging for 2 hours at 3000r/min, washing, and vacuum drying at 80 ℃ to obtain a modified graphene material which can obviously improve the corrosion resistance and the heat conductivity of the polyurea sealant;

(2) And (2) preparing a component A: in a nitrogen environment, 50 parts of polyol neopentyl glycol is heated to 80 ℃ and dehydrated for 1h, then cooled to 45 ℃, 70 parts of polyisocyanate cyclohexane dimethylene diisocyanate and 20 parts of amino chain extender N, N _, -dihydroxyl (diisopropyl) aniline are added, the mixture is heated to 85 ℃ to react for 2h, the reaction is stopped after the NCO value is measured by a dibutylamine titration method, and the reduced pressure rotary evaporation is carried out, so that a rapid film forming component is obtained;

(3) Preparation of component B: 70 parts of aminopolyether, 3 parts of modified resin fluorine modified aspartic acid ester F285018 parts of stabilizer benzoic acid, 3 parts of dispersant polyacrylate, 8 parts of zinc powder, 2 parts of anti-sedimentation wax, 1 part of pigment and 3 parts of corrosion inhibitor benzotriazole are stirred and dispersed for 1 hour, and the materials are ground and filtered after being uniformly mixed to obtain an adhesion material;

the weight portions are as follows: 155 parts of rapid film forming components, 10 parts of modified graphene materials and 111 parts of adhesion materials are mixed to obtain the heat-conducting corrosion-resistant polyurea sealant.

Comparative example 1

This comparative example is identical to the preparation procedure of example 1, except that the polyurea sealant does not contain modified graphene materials, specifically:

A preparation method of polyurea sealant comprises the following steps:

(1) And (2) preparing a component A: heating 30 parts of polyol 1, 4-cyclohexanediol to 90 ℃ in a nitrogen environment, dehydrating for 1h, cooling to 45 ℃, adding 50 parts of polyisocyanate isophorone diisocyanate and 20 parts of amino chain extender ethylenediamine, heating to 80 ℃ for crosslinking reaction for 2h, stopping the reaction after determining NCO value by a dibutylamine titration method, and performing reduced pressure rotary evaporation to obtain a rapid film forming component;

(2) Preparation of component B: 40 parts of aminopolyether, 1 part of modified resin fluorine modified aspartic acid ester F52015 parts, 1 part of stabilizer tartaric acid, 2 parts of dispersing agent calcium phosphate, 5 parts of zinc powder, 1 part of anti-sedimentation wax, 1 part of pigment and 2 parts of corrosion inhibitor sodium molybdate are mixed, stirred and dispersed for 0.5 hour, and the mixture is ground and filtered after uniform mixing to obtain an adhesion material;

(3) The weight portions are as follows: 80 parts of rapid film forming components and 65 parts of adhesion materials are mixed to obtain the polyurea sealant.

The specific application method of the heat-conducting corrosion-resistant polyurea sealant of the embodiments 1-3 is as follows: aiming at the problems of corrosion and leakage of fan radiators of 11#, 13#, 21# and 46# of Huaneng new energy Co., ltd, repair engineering practice is carried out: the leakage points of the radiator are precisely positioned by the infrared thermometer, then old paint films and corrosion products are rapidly removed, surface oil removal and dust treatment are carried out, the periphery of the leakage points are cleaned and wiped to be dry, dust-free, oil-free and rust-free, and the periphery of the leakage points is uniformly coated with the heat-conducting corrosion-resistant polyurea sealant, so that the sealant is rapidly solidified to form a film to seal the leakage points, and leakage of cooling media is prevented.

The polyurea sealant with excellent heat conduction and corrosion resistance is prepared in the embodiments 1-3, and the quick plugging of the radiator can be realized under the condition of no shutdown, and the heat conduction and corrosion resistance polyurea sealant prepared in the embodiment 1 is taken as an example for research, and the specific research method and the specific result are as follows:

1. And (3) testing heat conduction performance:

the heat conduction performance testing method comprises the following steps: the heat conductivity of the polyurea coating and the steel plate was measured by the transient plane heat source method of ASTM C518/C518M-17 Heat transfer coefficient Meter method using the heat conductive corrosion resistant polyurea sealant of example 1, and the results are shown in Table 1:

Table 1 comparative study of thermal conductivity

The results show that: compared with the polyurea sealant of the comparative example 1, the modified graphene material is added in the embodiment 1, so that the heat conductivity coefficient is improved by about 10 times; compared with the prior art, no matter whether the polyurea sealant belongs to a new formula or not, after the modified graphene material is added, the sealant attached to the radiator can realize effective heat dissipation of the radiator due to the excellent heat conductivity of graphene.

After graphene is added under the normal condition, as the graphene is granular, the dispersibility of the graphene is poor, the surface binding force of the sealant can be reduced, and after the graphene is modified by adopting a silane coupling agent, the adhesive force of the heat-conducting corrosion-resistant polyurea sealant prepared by adopting the modified graphene material is effectively enhanced, and the defect of the graphene is overcome.

2. Corrosion resistance test:

the application adopts a salt spray test method to test the corrosion resistance of the metal material, and further reflects the performance of the polyurea sealant.

Each tinplate was treated according to GB/T1771-2007, and then coated by a prescribed method, dried and conditioned. The test surface of the salt spray test sample is upward, forms 15-30 degrees with the vertical direction and forms 20 degrees as far as possible; dissolving sodium chloride in distilled water or deionized water with the conductivity not exceeding 20 mu S/cm, wherein the concentration of the sodium chloride is 50 g/L+/-5 g/L, and regulating the pH value to be between 6.5 and 7.2; setting the temperature in the salt fog box to 35+/-2 ℃, requiring the sedimentation rate of salt fog to be 1-3 mL/80cm ² h, setting the parameters, placing the sample in the salt fog box for testing, periodically checking the test plate in the process, rapidly taking out the test plate from the equipment after the test plate is finished, immediately drying the test plate after removing the residues of the test solution, and checking the damage phenomenon of the surface of the test plate.

After 1000 hours of neutral continuous spray salt spray test, the heat-conducting corrosion-resistant polyurea sealant coating sample of the embodiment 1 has uniform surface color and luster, and does not have the adverse phenomena of rust, corrosion, foaming, cracking, falling and the like, which indicates that the sealant sample has excellent corrosion resistance.

The neutral salt spray test is a laboratory test for artificially simulating the atmosphere salt spray environment, compared with the natural environment, the salt concentration of the chloride in the salt spray environment is several times or tens times of the salt spray content in the common natural environment, so that the corrosion speed is greatly improved, and the time for obtaining the result is also greatly shortened when the salt spray test is carried out on the product. Through salt spray tests, corrosion resistance data of the metal material or the corrosion-resistant coating can be obtained, so that the durability and reliability of the metal material or the corrosion-resistant coating in a marine environment can be evaluated. Although salt spray testing is an effective test method, the results may not be entirely representative of the situation in an actual use environment because it simulates a particular corrosive environment. Therefore, the corrosion resistance test is only completed in a laboratory for 1000 hours, the longer-time detection laboratory is not performed any more, and the obtained product is directly subjected to engineering demonstration application.

It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

Claims (10)

1. The heat-conducting corrosion-resistant polyurea sealant is characterized by being prepared from the following raw materials in parts by weight: 5-10 parts of modified graphene material, 80-155 parts of rapid film forming component and 65-111 parts of adhesion material;

And (3) modifying the graphene material by using a silane coupling agent as a modifier through a surface modification reaction to obtain a modified graphene material.

2. The heat-conducting corrosion-resistant polyurea sealant according to claim 1, wherein the surface modification reaction method comprises the following steps: and (3) hydrolyzing the silane coupling agent under an acidic condition, and reacting with the graphene material under a neutral condition to obtain the modified graphene material.

3. The heat-conducting corrosion-resistant polyurea sealant according to claim 1, wherein the mass ratio of the silane coupling agent to the graphene is 1:1-6.

4. The thermally conductive corrosion resistant polyurea sealant according to claim 1, wherein the graphene material is selected from the group consisting of graphene and graphene oxide; the silane coupling agent is selected from bis [ gamma- (triethoxysilyl) propyl ] tetrasulfide silane, 3-aminopropyl triethylsilane, (3-glycidoxy) trimethoxysilane or gamma- (methacryloyloxy) propyl trimethoxysilane.

5. The heat-conducting corrosion-resistant polyurea sealant according to claim 1, wherein the adhesive material is prepared from the following raw materials in parts by weight: 40-70 parts of aminopolyether, 15-20 parts of modified resin, 1-3 parts of stabilizer, 1-4 parts of dispersing agent, 5-8 parts of zinc powder, 1-2 parts of anti-sedimentation wax, 1 part of pigment and 1-3 parts of corrosion inhibitor.

6. The heat-conducting corrosion-resistant polyurea sealant according to claim 5, wherein the modified resin is one or more selected from fluorine modified aspartic acid ester F520, F220, F420, F2850 and F421, the stabilizer is one or more selected from tartaric acid or benzoic acid, the dispersing agent is one or more selected from calcium phosphate, aluminum phosphate, polysiloxane, silicone, ammonium polyacrylate and polyacrylate, and the corrosion inhibitor is one or more selected from sodium molybdate, organic phosphonic acid, azyl benzothiazole, benzotriazole and amino acid.

7. The heat-conducting corrosion-resistant polyurea sealant according to claim 1, wherein the rapid film forming component is polyurethane, and the polyurethane is prepared from the following raw materials in parts by weight: 30-50 parts of polyalcohol, 40-70 parts of polyisocyanate and 10-35 parts of amino chain extender.

8. The heat-conducting corrosion-resistant polyurea sealant according to claim 7, wherein the rapid prototyping composition is prepared by the steps of:

and mixing the dehydrated polyol, polyisocyanate and amino chain extender in a nitrogen environment, and carrying out polymerization reaction to obtain polyurethane.

9. A method for preparing the heat-conducting corrosion-resistant polyurea sealant according to claim 1, which is characterized by comprising the following steps:

and mixing the rapid film forming component, the modified graphene material and the adhesion material to obtain the heat-conducting corrosion-resistant polyurea sealant.

10. The use of the heat-conducting corrosion-resistant polyurea sealant according to claim 1 in the preparation of a sealant for repairing leakage of an offshore wind power radiator.