Formula and method of self-repairing material for surface insulation of electrical equipment

Abstract

The invention discloses a self-repairing material formula for surface insulation of power equipment and a method. The method comprises the following steps: step S1, material selection; s2, preparing a substrate; step S21, pretreatment of polyether amine; step S22, preparation of an isocyanate prepolymer; step S23, preparing the self-repairing polyurea; the self-repairing material is obtained by the preparation method. Compared with a traditional insulating material, the polyurea material has better mechanical performance and electrical performance and can be used as external insulation of power equipment, flashover faults are prevented, and safe operation of the power equipment is guaranteed. Meanwhile, the polyurea-based material can be self-repaired under the condition of damage, and the performance of the polyurea-based material can be recovered to about 90% of the performance of the original material, so that the maintenance workload of power equipment is reduced, and the maintenance cost and the labor cost are reduced; the self-repairing material disclosed by the invention has good mechanical performance and electrical performance, also has certain self-repairing performance, and meets the material use requirements of various scenes.

Description

Technical Field

[0001] The invention belongs to the technical field of insulating materials, and in particular relates to a formula and method of a self-repairing material for surface insulation of electric equipment. Background Art

[0002] Polyurea (PUA) is one of the most common, widely used and most studied materials in the world. It is also a high-performance polymer that has shown broad application prospects in many fields such as construction, aerospace, automobiles, and electronics in recent years. Polyurea has excellent strength and wear resistance, and can withstand high tensile strength and wear resistance. At the same time, it has good corrosion resistance to many chemicals, can resist the erosion of acids, alkalis, solvents and some chemicals, can be used for a long time in outdoor environments without being affected by ultraviolet rays, oxidation and temperature changes, and shows excellent weather resistance and aging resistance. It can maintain stable performance over a wide temperature range, maintaining flexibility at low temperatures and strength and stability at high temperatures.

[0003] Polyurea materials are widely used in building sealing, waterproofing, moisture-proofing, heat insulation, and thermal insulation. For example, they are used in building roof waterproofing, industrial plants, cold storage vapor barriers, reservoirs, bridges and cross-sea bridges, tunnels, underground projects, power plant cooling towers, sewage treatment tanks, aquariums, swimming pool lining decoration and other fields. At the same time, polyurea materials are also used to manufacture structural materials for aerospace, fuel storage tanks, hydraulic systems, electrical insulation materials, etc. The performance advantages of polyurea are mainly reflected in the following aspects:

[0004] (1) Excellent physical properties: Polyurea materials can withstand large external forces and deformations. Under extreme conditions, they can maintain structural integrity and stability and are not prone to permanent deformation. This property is particularly important for applications that need to withstand heavy loads, dynamic loads or cyclic stresses, such as the protection and repair of structural parts such as bridges, tunnels, and large mechanical equipment. Polyurea materials also have excellent wear resistance. In the process of long-term friction and wear, it can effectively resist wear and keep the surface of the material flat and smooth. This feature gives polyurea significant advantages in situations where frequent contact and friction are required, such as floors, conveyor belts, and inner walls of pipes.

[0005] (2) Excellent chemical corrosion resistance: Polyurea materials have excellent corrosion resistance and show extraordinary stability in many chemical environments. It can withstand a variety of corrosive chemicals, including strong acids, strong alkalis, various salts, and greases. Even in harsh chemical environments, it can maintain its original physical and chemical properties for a long time. This wide range of corrosion resistance makes polyurea materials have great application potential in the chemical, petroleum, and natural gas industries. As an anti-corrosion coating for equipment, polyurea can effectively prevent the erosion of corrosive substances, extend the service life of equipment, reduce maintenance costs, and provide strong protection for the safe production of these industries.

[0006] (3) Good weather resistance and aging resistance: Polyurea materials have excellent weather resistance and good stability in outdoor environments. They can withstand the erosion of natural factors such as sunlight, rain, wind and sand for a long time, and are not prone to aging and cracking even under extremely harsh climatic conditions. This excellent weather resistance makes polyurea materials have long-term durability in outdoor buildings, bridges, tunnels and other projects. Whether used as a waterproof layer, protective layer or decorative layer, polyurea can effectively resist the erosion of the natural environment, maintain the integrity and stability of the structure, extend the service life of the project, and provide strong support for people's production and life.

[0007] (4) Adjustable curing time and convenient construction: Polyurea materials have shown significant advantages in various projects with their flexible and diverse construction methods and adjustable curing time. It can be constructed by spraying, scraping, pouring and other methods to adapt to different construction environments and requirements. The curing speed of polyurea materials can be adjusted, and it can reach the use strength within the operable time, greatly shortening the construction period. This feature makes polyurea have great advantages in occasions that require a certain amount of construction time and repair, such as emergency repairs, temporary facility construction, etc., which can quickly restore the use function of the project and reduce losses caused by construction delays.

[0008] (5) Environmental protection and recyclability: During the production and use of polyurea materials, with its low environmental impact characteristics, it meets the current society's urgent need for green environmental protection. Its production process uses environmentally friendly raw materials and processes, effectively controls the emission of harmful substances, has little negative impact on the environment, and meets the environmental protection requirements of modern industry. What is even more rare is that after the polyurea material reaches the end of its service life or is discarded, it can be reused through specific recycling technologies and processes, which not only effectively reduces resource waste, but also significantly reduces environmental pollution caused by material disposal, reflecting the concept of circular economy and sustainable development.

[0009] Polyurea materials, with their excellent insulation properties and chemical stability, have important applications in power systems. As an insulating layer, they can effectively isolate current and prevent short circuits and leakage in electrical equipment, thereby ensuring the safe and stable operation of power systems. However, although polyurea materials perform well under normal conditions, once they suffer physical damage or aging damage from the outside, they cannot recover their functions like some advanced self-healing materials.

[0010] When the polyurea insulation layer is damaged, if it is not discovered and repaired in time, it is easy to cause insulation breakdown, which may lead to insulation flashover failure. Insulation flashover refers to the phenomenon that when the insulation layer of electrical equipment is damaged, due to excessive voltage or uneven electric field distribution, the current suddenly breaks through the insulation layer and forms a discharge channel. Damage to electrical equipment caused by insulation layer damage may cause large-scale power outages, which have a serious impact on people's daily life and industrial production.

[0011] Secondly, the damaged parts of the polyurea material need to be repainted, which is a complicated and time-consuming process. Since the construction of polyurea materials requires specific processes and equipment, and has high requirements for the construction environment, the secondary repainting not only requires a lot of manpower and material resources, but also has considerable costs. This not only increases the maintenance cost of the power system, but may also lead to more serious failures due to untimely repairs.

[0012] Therefore, in order to solve the above problems, a self-repairing material formulation and method for surface insulation of power equipment are proposed. Summary of the invention

[0013] The purpose of the present invention is to provide a self-repairing material formula and method for surface insulation of power equipment to solve the existing problems.

[0014] In order to solve the above technical problems, the present invention is achieved through the following technical solutions:

[0015] The present invention is a method for preparing a self-repairing material for surface insulation of electric power equipment, comprising the following steps:

[0016] Step S1: Material selection

[0017] Selection of isocyanate: Toluene diisocyanate (TDI) and diphenylmethane diisocyanate (MDI) are selected as isocyanate raw materials;

[0018] Catalyst selection: Dibutyltin dilaurate (DBTDL, 95%) was selected as the catalyst for the reaction;

[0019] Selection of amine compounds: polyetheramine D400 and polyetheramine D2000 are selected as chain extenders; 4,4'-diaminodiphenyl disulfide (DTDA) and boric acid (BA) are selected as crosslinking agents;

[0020] Step S2: Matrix preparation

[0021] Step S21: Pretreatment of polyetheramine

[0022] Weigh polyetheramine D400 and polyetheramine D2000 according to a certain mass ratio of 100:50, dissolve the weighed polyetheramine D400 and polyetheramine D2000 in 100 mL of dimethylformamide, and put them into a three-necked flask equipped with a vacuum pump, a condensing device, a mechanical stirrer and a thermometer, and dehydrate at 110° C. for 1.5 h; when the reaction temperature drops to 70° C., turn off the vacuum pump and fill the three-necked flask with N2;

[0023] Step S22: Preparation of isocyanate prepolymer

[0024] According to the mass proportion of the polyetheramine, 140 mass parts of isocyanate, 50 mass parts of toluene diisocyanate (TDI) and 100 mass parts of diphenylmethane diisocyanate (MDI) are weighed; the isocyanate is dissolved in 80 mL of dimethylformamide, added to a dropping funnel, and added dropwise to the polyetheramine solution for about 30 minutes; the reaction temperature is 60° C., the mixture is stirred sufficiently, the reaction time is about 12 hours, and Fourier infrared spectroscopy is used to determine whether urea group -HNCONH- is generated;

[0025] Step S23: Preparation of self-repairing polyurea

[0026] Weigh x parts by mass of 4,4'-diaminodiphenyl disulfide and y parts by mass of boric acid (BA), dissolve them in 30 mL of dimethylformamide, add them to a dropping funnel, and add them dropwise to the isocyanate prepolymer solution for about 30 minutes. The reaction temperature is 80 degrees Celsius and the reaction time is 12 hours.

[0027] Sample preparation: Pour the self-healing polyurea solution into a polytetrafluoroethylene mold and place it in a vacuum oven with an evaporation temperature of 100 degrees Celsius and an evaporation time of 24 hours. After complete curing, take out the sample and cool it to room temperature for subsequent performance testing.

[0028] Preferably, in step S23, the ratio of the mass fraction x of 4,4'-diaminodiphenyl disulfide to the mass fraction y of boric acid (BA) is 6:4.

[0029] Preferably, in step S1, toluene diisocyanate (TDI) and diphenylmethane diisocyanate (MDI) are selected as isocyanate raw materials, so that the prepared polyurea has better mechanical properties and mechanical properties.

[0030] Preferably, in step S1, dibutyltin dilaurate (DBTDL, 95%) is selected as a catalyst for the reaction to accelerate the reaction rate and increase the curing speed, and the appropriate amount of catalyst added is adjusted according to the usage scenario.

[0031] Preferably, in step S1, polyetheramine D400 and polyetheramine D2000 are selected as chain extenders to make the isocyanate prepolymer molecular chain longer and improve its tensile properties; at the same time, 4,4'-diaminodiphenyl disulfide (DTDA) and boric acid (BA) are selected as crosslinking agents to form multiple crosslinking points in the polyurea material and improve the crosslinking density.

[0032] A self-repairing material for surface insulation of electric equipment is obtained by the above preparation method.

[0033] The present invention has the following beneficial effects:

[0034] The polyurea material in the present invention has better mechanical and electrical properties than traditional insulating materials, and can be used as external insulation for power equipment to prevent flashover failures and ensure safe operation of power equipment. At the same time, the polyurea-based material can self-repair in the event of damage and can recover to about 90% of the original material performance, reducing the maintenance workload of power equipment, maintenance costs and labor costs.

[0035] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0037] Figure 1 A flowchart of a method for using a self-repairing material for surface insulation of power equipment;

[0038] Figure 2 This is a dynamic contact angle test diagram of a self-healing material used for surface insulation of power equipment;

[0039] Figure 3 This is a microscopic morphology characterization test diagram of a self-healing material used for surface insulation of power equipment;

[0040] Figure 4 This is a line graph of the elongation at break test of a self-repairing material used for surface insulation of power equipment;

[0041] Figure 5This is a line graph of the tensile strength test of a self-healing material used for surface insulation of power equipment;

[0042] Figure 6 This is a breakdown strength diagram of a self-healing material used for surface insulation of power equipment. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] In the description of the present invention, it should be understood that the terms "upper", "middle", "outer", "inner" and the like indicating directions or positional relationships are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the components or elements referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0045] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] See also Figure 1-Figure 6 As shown, the present invention is a method for using a self-repairing material for surface insulation of power equipment, comprising the following steps:

[0047] Step S1: Material selection

[0048] Selection of isocyanate: Toluene diisocyanate (TDI) and diphenylmethane diisocyanate (MDI) are selected as isocyanate raw materials;

[0049] Catalyst selection: Dibutyltin dilaurate (DBTDL, 95%) was selected as the catalyst for the reaction;

[0050] Selection of amine compounds: polyetheramine D400 and polyetheramine D2000 are selected as chain extenders; 4,4'-diaminodiphenyl disulfide (DTDA) and boric acid (BA) are selected as crosslinking agents;

[0051] Step S2: Matrix preparation

[0052] Step S21: Pretreatment of polyetheramine

[0053] Weigh polyetheramine D400 and polyetheramine D2000 according to a certain mass ratio of 100:50, dissolve the weighed polyetheramine D400 and polyetheramine D2000 in 100 mL of dimethylformamide, and put them into a three-necked flask equipped with a vacuum pump, a condensing device, a mechanical stirrer and a thermometer, and dehydrate at 110° C. for 1.5 h; when the reaction temperature drops to 70° C., turn off the vacuum pump and fill the three-necked flask with N2;

[0054] Step S22: Preparation of isocyanate prepolymer

[0055] According to the mass proportion of the polyetheramine, 140 mass parts of isocyanate, 50 mass parts of toluene diisocyanate (TDI) and 100 mass parts of diphenylmethane diisocyanate (MDI) are weighed; the isocyanate is dissolved in 80 mL of dimethylformamide, added to a dropping funnel, and added dropwise to the polyetheramine solution for about 30 minutes; the reaction temperature is 60° C., the mixture is stirred sufficiently, the reaction time is about 12 hours, and Fourier infrared spectroscopy is used to determine whether urea group -HNCONH- is generated;

[0056] Step S23: Preparation of self-repairing polyurea

[0057] Weigh x parts by mass of 4,4'-diaminodiphenyl disulfide and y parts by mass of boric acid (BA), dissolve them in 30 mL of dimethylformamide, add them to a dropping funnel, and add them dropwise to the isocyanate prepolymer solution for about 30 minutes. The reaction temperature is 80 degrees Celsius and the reaction time is 12 hours.

[0058] Sample preparation: Pour the self-healing polyurea solution into a polytetrafluoroethylene mold and place it in a vacuum oven with an evaporation temperature of 100 degrees Celsius and an evaporation time of 24 hours. After complete curing, take out the sample and cool it to room temperature for subsequent performance testing.

[0059] In one embodiment, in step S23, the ratio of the mass fraction x of 4,4'-diaminodiphenyl disulfide to the mass fraction y of boric acid (BA) is 6:4.

[0060] In one embodiment, in step S1, toluene diisocyanate (TDI) and diphenylmethane diisocyanate (MDI) are selected as isocyanate raw materials, so that the prepared polyurea has better mechanical properties and mechanical properties.

[0061] In one of the embodiments, in step S1, dibutyltin dilaurate (DBTDL, 95%) is selected as a catalyst for the reaction to accelerate the reaction rate and increase the curing speed, and the appropriate amount of catalyst added is adjusted according to the usage scenario.

[0062] In one embodiment, in step S1, polyetheramine D400 and polyetheramine D2000 are selected as chain extenders to make the molecular chain of isocyanate prepolymer longer and improve its tensile properties; at the same time, 4,4'-diaminodiphenyl disulfide (DTDA) and boric acid (BA) are selected as cross-linking agents to form multiple cross-linking points in the polyurea material and improve the cross-linking density.

[0063] A self-repairing material for surface insulation of electric equipment is obtained by the above preparation method.

[0064] This example is a performance test of a self-repairing material for surface insulation of power equipment:

[0065] Weigh x parts by mass of 4,4'-diaminodiphenyl disulfide and y parts by mass of boric acid (BA) (x:y are 8:2, 6:4, 4:6, 2:8 respectively), dissolve in 30 mL of dimethylformamide, add to a dropping funnel, and add dropwise to the isocyanate prepolymer solution for about 30 minutes. The reaction temperature is 80 degrees Celsius and the reaction time is 12 hours.

[0066] Sample preparation: Pour the self-healing polyurea solution into a polytetrafluoroethylene mold and place it in a vacuum oven with an evaporation temperature of 100 degrees Celsius and an evaporation time of 24 hours. After complete curing, take out the sample and cool it to room temperature for subsequent performance testing.

[0067] Sample number 1# with x:y=8:2, sample number 2# with x:y=6:4, sample number 3# with x:y=4:6, and sample number 4# with x:y=2:8.

[0068] like Figure 2-Figure 6 As shown, this embodiment is a self-repairing performance test of a self-repairing material for surface insulation of power equipment: a dumbbell-shaped mold is prepared, and its tensile strength and elongation at break before and after cutting are tested.

[0069] According to the experimental results, the smaller the ratio between x parts by mass of 4,4'-diaminodiphenyl disulfide and y parts by mass of boric acid (BA), the smaller the dynamic contact angle and the hydrophobic performance. However, according to the scanning electron microscope (SEM) test results, the fracture surface becomes smoother and smoother as the ratio of x parts by mass of 4,4'-diaminodiphenyl disulfide and y parts by mass of boric acid decreases, and the fracture mode becomes more brittle. According to the self-healing performance test results, before and after the repair, its tensile strength and elongation at break can be repaired to more than 85% of the original sample, and it has good self-healing ability. According to the breakdown voltage test, its average breakdown voltage is above 20kV / mm, with high insulation capacity, meeting the electrical requirements of insulating shell materials.

[0070] It should be further explained that the self-healing material of the present invention, namely the polyurea material, can be brushed onto the casing of the power equipment. The insulating layer formed by curing is not limited by the shape of the power device and can be quickly brushed on; the prepared polyurea material has a relatively moderate viscosity, and the curing time can be adjusted by adjusting the amount of catalyst to adjust the curing speed and ensure the brushing operation time; the self-healing material has good mechanical and electrical properties, as well as certain self-healing properties, which meets the material use requirements in various scenarios.

[0071] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0072] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for preparing a self-repairing material for surface insulation of electric power equipment, characterized in that: The following steps are involved: Step S1: Material selection Selection of isocyanate: Toluene diisocyanate (TDI) and diphenylmethane diisocyanate (MDI) are selected as isocyanate raw materials; Catalyst selection: Dibutyltin dilaurate (DBTDL, 95%) was selected as the catalyst for the reaction; Selection of amine compounds: polyetheramine D400 and polyetheramine D2000 are selected as chain extenders; 4,4'-diaminodiphenyl disulfide (DTDA) and boric acid (BA) are selected as crosslinking agents; Step S2: Matrix preparation Step S21: Pretreatment of polyetheramine Weigh polyetheramine D400 and polyetheramine D2000 according to a certain mass ratio of 100:50, dissolve the weighed polyetheramine D400 and polyetheramine D2000 in 100 mL of dimethylformamide, and put them into a three-necked flask equipped with a vacuum pump, a condensing device, a mechanical stirrer and a thermometer, and dehydrate at 110° C. for 1.5 h; when the reaction temperature drops to 70° C., turn off the vacuum pump and fill the three-necked flask with N2; Step S22: Preparation of isocyanate prepolymer According to the mass proportion of the polyetheramine, 140 mass parts of isocyanate, 50 mass parts of toluene diisocyanate (TDI) and 100 mass parts of diphenylmethane diisocyanate (MDI) are weighed; the isocyanate is dissolved in 80 mL of dimethylformamide, added to a dropping funnel, and added dropwise to the polyetheramine solution for about 30 minutes; the reaction temperature is 60° C., the mixture is stirred sufficiently, the reaction time is about 12 hours, and Fourier infrared spectroscopy is used to determine whether urea group -HNCONH- is generated; Step S23: Preparation of self-repairing polyurea Weigh x parts by mass of 4,4'-diaminodiphenyl disulfide and y parts by mass of boric acid (BA), dissolve them in 30 mL of dimethylformamide, add them to a dropping funnel, and add them dropwise to the isocyanate prepolymer solution for about 30 minutes. The reaction temperature is 80 degrees Celsius and the reaction time is 12 hours. Sample preparation: Pour the self-healing polyurea solution into a polytetrafluoroethylene mold and place it in a vacuum oven with an evaporation temperature of 100 degrees Celsius and an evaporation time of 24 hours. After complete curing, take out the sample and cool it to room temperature for subsequent performance testing.

2. The method of preparing a self-repairing material for surface insulation of electric power equipment according to claim 1, characterized in that: In the step S23, the ratio of the mass fraction x of 4,4'-diaminodiphenyl disulfide to the mass fraction y of boric acid (BA) is 6:

4.

3. The method of preparing a self-repairing material for surface insulation of electric power equipment according to claim 1, characterized in that: In the step S1, toluene diisocyanate (TDI) and diphenylmethane diisocyanate (MDI) are selected as isocyanate raw materials, so that the prepared polyurea has better mechanical properties and mechanical properties.

4. The method of preparing a self-repairing material for surface insulation of electric power equipment according to claim 1, characterized in that: In the step S1, dibutyltin dilaurate (DBTDL, 95%) is selected as a catalyst for the reaction to accelerate the reaction rate and improve the curing speed, and the appropriate amount of catalyst added is adjusted according to the usage scenario.

5. The method for preparing a self-repairing material for surface insulation of electric power equipment according to claim 1, characterized in that: In step S1, polyetheramine D400 and polyetheramine D2000 are selected as chain extenders to make the molecular chain of isocyanate prepolymer longer and improve its tensile properties; at the same time, 4,4'-diaminodiphenyl disulfide (DTDA) and boric acid (BA) are selected as crosslinking agents to form multiple crosslinking points in the polyurea material and improve the crosslinking density.

6. A self-repairing material for surface insulation of electric power equipment obtained according to the method according to any one of claims 1 to 5.

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