Lightweight high-insulation core composite material and preparation method and application thereof

Abstract

The invention provides a lightweight high-insulation core composite material as well as a preparation method and application thereof, and relates to the technical field of lightweight high-insulation core composite materials. According to the invention, the foam core body with a uniform foam structure is subjected to fiber reinforcement, so that the foam core body has excellent electrical insulation performance, the pollution flashover phenomenon is reduced, the long-term stability of the material is ensured, the reliability of equipment is improved, and the service life of the equipment is prolonged. Through combination of the light core body and the fiber reinforcement layer, the composite material can effectively meet the requirements of high-voltage and ultra-high-voltage power transmission environments when being used as a post insulator, and the preparation method of the composite material provided by the invention has a simple process flow and high production efficiency, and is suitable for large-scale popularization and application.

Description

Technical Field

[0001] The invention relates to the technical field of lightweight high-insulation core composite materials, and in particular to a lightweight high-insulation core composite material and a preparation method and application thereof. Background Art

[0002] Insulators are an important component of the power system. They are mainly used to support and insulate electrical conductors to prevent current leakage and short circuits. Their main functions include supporting electrical conductors, insulating and resisting environmental factors. There are many materials and types of insulators, the most common of which are porcelain insulators, glass insulators and composite insulators. Porcelain insulation is resistant to high temperatures and corrosion, but it is fragile; glass insulators have good transparency, high mechanical strength and good durability, but are relatively heavy; composite insulators are made of polymer materials, are resistant to pollution flashover, and are suitable for ultra-high voltage and complex environments. With the growth of electricity demand and the development of technology, the performance requirements for insulators are also constantly increasing. Therefore, composite insulators are becoming more and more widely used because they can maintain stable insulation performance in harsh environments.

[0003] However, most of the current composite post insulators are made of solid materials, which leads to high preparation costs and heavy weight, especially when manufacturing large-diameter composite insulators. These problems are particularly prominent. This design not only increases the production and transportation costs of the equipment, but may also affect the installation and maintenance of the insulators and their stability during long-term use. Therefore, it is urgent to develop a new lightweight material and a preparation process adapted to it to reduce the preparation cost of composite post insulators, reduce the weight of the equipment, and maintain or improve the insulation performance and mechanical strength of the material, so as to better meet the requirements of high-voltage and ultra-high-voltage power systems for high insulation, light weight, low cost and high mechanical strength of post insulators, and ensure the long-term stability of the material during use. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide a lightweight high-insulation core composite material and its preparation method and application. The present invention performs fiber reinforcement on a foam core with a uniform pore structure, so that the composite material has excellent and stable electrical insulation performance, reduces the occurrence of flashover, ensures the long-term stability of the composite material during use, and improves the reliability and service life of the equipment.

[0005] The present invention provides a lightweight high-insulation core composite material, which is obtained by fiber-reinforced foam core, wherein the foam core is prepared from raw materials including the following components:

[0006] 80-120 parts by weight of epoxy resin;

[0007] 60-100 parts by weight of curing agent;

[0008] 2 to 6 parts by weight of polymer microspheres;

[0009] Accelerator 0.5-1.5 parts by mass

[0010] Preferably, the epoxy resin is bisphenol A epoxy resin.

[0011] Preferably, the curing agent is an anhydride curing agent.

[0012] Preferably, the polymer microspheres are expandable microspheres.

[0013] Preferably, the fiber is high-strength glass fiber.

[0014] The present invention also provides an application of a lightweight high-insulation core composite material in a post insulator, wherein the lightweight high-insulation core composite material is the lightweight high-insulation core composite material described in the above technical solution.

[0015] Preferably, the post insulator is a post insulator in a high voltage or ultra-high voltage transmission line.

[0016] The present invention also provides a method for preparing a lightweight high-insulation core composite material, comprising the following steps:

[0017] Firstly, a foam core with a uniform pore structure is prepared, and then a fiber cloth is wound on the surface of the core, vacuum impregnated with epoxy resin and then cured to obtain a lightweight and highly insulating core composite material.

[0018] Compared with the prior art, the present invention uses epoxy resin as the matrix, fills the lightweight core with polymer microspheres, and combines the impregnation and curing process of the fiber reinforcement layer, so that the core structure has excellent and stable electrical insulation performance, which can effectively meet the electrical requirements in high-voltage and ultra-high-voltage power transmission environments, and ensure that the material can still maintain a reliable insulation effect under long-term use. The present invention effectively improves the material's pollution flashover resistance by performing fiber reinforcement on the outer layer of the core, so that it can reduce the occurrence of pollution flashover in a severely polluted environment and improve the reliability and service life of the equipment. The preparation process of the lightweight and highly insulating core composite material of the present invention is relatively simple and has high production efficiency. It can complete the preparation of the material in a relatively short period of time, reduce production costs, and is suitable for large-scale promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described below in conjunction with the accompanying drawings.

[0020] Figure 1 It is a schematic structural diagram of a lightweight and highly insulating core composite material of the present invention;

[0021] Figure 2These are the dye penetration test results of the samples of the present invention, wherein a is the dye penetration test result of the samples of Example 1, b is the dye penetration test result of the samples of Comparative Example 1, and c is the dye penetration test result of the samples of Comparative Example 2.

[0022] Explanation of reference numerals: 1. Fiber reinforcement layer; 2. Foam core. DETAILED DESCRIPTION

[0023] The technical solution of the present invention will be clearly and completely described below in conjunction with 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.

[0024] The present invention provides a lightweight high-insulation core composite material, which is obtained by fiber-reinforced foam core, wherein the foam core is prepared from raw materials of the following components:

[0025] 80-120 parts by weight of epoxy resin;

[0026] 60-100 parts by weight of curing agent;

[0027] 2 to 6 parts by weight of polymer microspheres;

[0028] Accelerator 0.5-1.5 parts by mass

[0029] In a preferred embodiment of the present invention, the foam core is prepared from the following raw materials:

[0030] 100 parts by mass of epoxy resin;

[0031] 80 parts by mass of curing agent;

[0032] 4 parts by mass of polymer microspheres;

[0033] 1 part by mass of accelerator.

[0034] In some specific embodiments of the present invention, the epoxy resin is preferably a bisphenol A epoxy resin. In some preferred embodiments of the present invention, the epoxy resin is bisphenol A diglycidyl ether (DGEBA).

[0035] In some specific embodiments of the present invention, the curing agent is preferably an anhydride curing agent. In some preferred embodiments of the present invention, the curing agent is methylhexahydrophthalic anhydride (MHHPA).

[0036] In some specific embodiments of the present invention, the polymer microspheres are preferably expandable microspheres. In some preferred embodiments of the present invention, the polymer microspheres are at least one of Aksu 909DU80, Aksu 920DU40, and Matsumoto MSH-550. In a specific embodiment of the present invention, the polymer microspheres are composed of Aksu 909DU80, Aksu 920DU40, and Matsumoto MSH-550 in a mass ratio of 1:1:1.

[0037] In some specific embodiments of the present invention, the fiber is preferably high-strength glass fiber. In some preferred embodiments of the present invention, the fiber is used in the form of fiber cloth.

[0038] The present invention also provides an application of a lightweight high-insulation core composite material in a post insulator, wherein the lightweight high-insulation core composite material is the lightweight high-insulation core composite material described in the above technical solution. The lightweight high-insulation core composite material of the present invention can also be extended to use in other structures or components with high insulation requirements.

[0039] The post insulators in some specific embodiments of the present invention are preferably post insulators in high voltage and ultra-high voltage transmission lines.

[0040] The present invention also provides a method for preparing a lightweight high-insulation core composite material, comprising the following steps:

[0041] S1, mixing epoxy resin, curing agent, polymer microspheres and accelerator evenly under vacuum conditions to obtain a foam material matrix;

[0042] S2, uniformly coating the mold surface with a release agent, and then pre-curing the foam matrix prepared in S1 in the mold, curing after the pre-curing, and demolding after the curing to obtain a foam core with a uniform pore structure;

[0043] S3. Cut the fiber cloth according to the size of the foam core prepared in S2, wrap the fiber cloth on the surface of the core, immerse the foam core wrapped with the fiber cloth in a mixture of epoxy resin and curing agent, and make the epoxy resin evenly impregnate into the fiber cloth under vacuum. After the fiber layer is fully impregnated with the resin, it is cured to obtain a lightweight and highly insulating core composite material.

[0044] In some specific embodiments of the present invention, the pre-curing temperature of S2 is preferably 60° C., the pre-curing time is preferably 2 h, the curing temperature is preferably 110° C., and the curing time is preferably 4 h.

[0045] In some specific embodiments of the present invention, the wrapping is performed by a wrapping machine.

[0046] In some specific embodiments of the present invention, the mass ratio of epoxy resin to curing agent in S3 is 100:30.

[0047] In some specific embodiments of the present invention, the curing temperature of S3 is preferably 100° C., and the curing time is preferably 12 h.

[0048] In some specific embodiments of the present invention, the method for preparing a lightweight and highly insulating core composite material also includes step S5, specifically: performing an appearance inspection on the lightweight and highly insulating core composite material prepared in S4 to ensure that there are no bubbles and cracks on the surface of the material, and then performing a performance test on the finished product to ensure that it meets the design requirements.

[0049] In order to further illustrate the present invention, the following examples are used to describe the raw materials in detail.

[0050] DGEBA was purchased from Nantong Phoenix Resin Factory; MHHPA was purchased from Zhejiang Bolim Co., Ltd.; the filler was polymer expandable microspheres, specifically: Akzo 909DU80, Akzo 920DU40, Matsumoto MSH-550; DMP-30 with a purity of 95% was purchased from Shanghai McLean Co., Ltd.

[0051] Unless otherwise specified, all experiments were repeated three times. SPSS 21.0 was used for analysis of variance (ANOVA) and Duncan's multiple comparison analysis. The results were expressed as mean ± SD. P < 0.05 indicated a significant difference.

[0052] Example 1

[0053] A lightweight high-insulation core composite material is prepared from the following raw materials:

[0054] DGEBA 100 parts by mass; MHHPA 80 parts by mass; polymer microspheres 4 parts by mass; DMP-30 1 part by mass;

[0055] The polymer microspheres are composed of Aksu 909DU80, Aksu 920DU40 and Matsumoto MSH-550 in a mass ratio of 1:1:1.

[0056] The steps of preparing the lightweight high-insulation core composite material are as follows:

[0057] S1. Using a planetary vacuum agitator (Marath, Mv-300), the epoxy resin, curing agent, polymer microspheres and accelerator are subjected to vacuum mechanical stirring (1200 r / min, 15 min) and degassing to obtain a foam material matrix;

[0058] S2, uniformly coating the mold surface with a release agent, and then pre-curing the foam material matrix prepared in S1 in the mold at 60° C. for 2 h, curing at 110° C. for 4 h after the pre-curing, and demolding after the curing to obtain a foam core with a uniform pore structure;

[0059] S3. Cut the fiber cloth according to the size of the foam core prepared in S2, wrap the fiber cloth on the surface of the core, immerse the foam core wrapped with the fiber cloth in a mixture of epoxy resin and curing agent in a mass ratio of 100:30, and vacuum-impregnate the epoxy resin into the fiber cloth uniformly. After the fiber layer is fully impregnated with the resin, cure it at 100°C for 12 hours to obtain a lightweight and highly insulating core composite material.

[0060] Comparative Example 1

[0061] Same as Example 1, except that polyurethane foam of the same specification is used to replace the foam core.

[0062] Comparative Example 2

[0063] Same as Example 1, except that basalt fiber cloth is used instead of glass fiber cloth.

[0064] Test Example 1

[0065] (1) The density of the samples prepared in the examples and comparative examples was tested using the standard water displacement method. The results are shown in Table 1.

[0066] Table 1 Sample density

[0067] sample <![CDATA[Density (g / cm 3 )]]> Example 1 0.58±0.01 Comparative Example 1 1.07±0.02 Comparative Example 2 2.15±0.04

[0068] It can be seen from Table 1 that the density of the lightweight high-insulation core composite material of the present invention is significantly reduced, so it can greatly reduce the weight of high-voltage power transmission equipment and meet the lightweight requirements of the equipment.

[0069] (2) Dye penetration test: The dye penetration method relies on the capillary action of the test solution to determine whether there are defects at the interface between the fiber reinforcement layer and the foam core. Figure 2 shown.

[0070] Depend on Figure 2 It can be seen that the three samples in the test did not have the phenomenon of dye liquid penetrating within 15 minutes, and no part of the sample attracted the dye solution to the surface through capillary action. The results show that the composite material obtained by the vacuum impregnation epoxy resin fiber reinforcement method of the present invention has good interface bonding, and there are no defects in the upper and lower parts of the entire sample, which is an ideal reinforcement method.

[0071] (3) Breakdown strength test: It was carried out in transformer oil according to GB / T 1408.1-2016. The sample thickness was 2±0.1 mm. The ball electrodes were placed at the core interface and the glass fiber composite material respectively. The voltage was increased at a rate of 1 kV / s until breakdown. The breakdown strength of the material was recorded. The results are shown in Table 2.

[0072] Table 2 Sample impact strength sample Breakdown strength (kV / mm) Example 1 7.44±0.12 Comparative Example 1 5.65±0.15 Comparative Example 2 6.72±0.11

[0073] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. A lightweight high insulation core composite material, characterized in that: The foam core is obtained by fiber reinforcement, wherein the foam core is prepared from raw materials including the following components: 80-120 parts by mass of epoxy resin; 60-100 parts by weight of curing agent; 2 to 6 parts by weight of polymer microspheres; Accelerator 0.5-1.5 parts by mass 2. A lightweight and highly insulating core composite material according to claim 1, characterized in that: The epoxy resin is bisphenol A type epoxy resin.

3. A lightweight and highly insulating core composite material according to claim 1, characterized in that: The curing agent is an anhydride curing agent.

4. The lightweight and highly insulating core composite material according to claim 1, characterized in that: The polymer microspheres are expandable microspheres.

5. The lightweight and highly insulating core composite material according to claim 1, characterized in that: The fiber is high-strength glass fiber.

6. The method for preparing the lightweight high insulation core composite material according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1, mixing epoxy resin, curing agent, polymer microspheres and accelerator evenly under vacuum conditions to obtain a foam material matrix; S2, uniformly coating the mold surface with a release agent, and then pre-curing the foam matrix prepared in S1 in the mold, curing after the pre-curing, and demolding after the curing to obtain a foam core with a uniform pore structure; S3. Cut the fiber cloth according to the size of the foam core prepared in S2, wrap the fiber cloth on the surface of the core, immerse the foam core wrapped with the fiber cloth in a mixture of epoxy resin and curing agent, and make the epoxy resin evenly impregnate into the fiber cloth under vacuum. After the fiber layer is fully impregnated with the resin, it is cured to obtain a lightweight and highly insulating core composite material.

7. The preparation method according to claim 6, characterized in that: The pre-curing temperature of S2 is 60° C., the pre-curing time is 2 hours, the curing temperature is 110° C., and the curing time is 4 hours.

8. The preparation method according to claim 6, characterized in that: The curing temperature of S3 is 100° C. and the curing time is 12 h.

9. Application of a lightweight high-insulation core composite material in a post insulator, characterized in that: The lightweight high-insulation core composite material is the lightweight high-insulation core composite material described in any one of claims 1 to 5 or the lightweight high-insulation core composite material prepared by the preparation method described in any one of claims 6 to 8.

10. The use according to claim 9, characterized in that: The post insulator is a post insulator in a high voltage or ultra-high voltage transmission line.

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